JP3458663B2 - Vehicle driving force control device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for controlling the driving force of a vehicle, and more specifically, to the driving force of the vehicle in order to enhance the operability and drivability of the vehicle in accordance with the surrounding conditions of the vehicle while traveling. The present invention relates to a control device that appropriately controls.

[0002]

2. Description of the Related Art Conventionally, the traveling characteristics of a vehicle are corrected according to the road conditions and the driving characteristics of the driver, and, for example, when there is a vehicle in front of the vehicle, an automatic brake is used to make a collision. Many preventive safety measures have been devised to avoid such problems, and the development of more comfortable driving has become active.

However, when the automatic braking is used to avoid the obstacle in front of the vehicle as described above,
A sudden deceleration shock that does not meet the driver's intention may occur.

Therefore, when it is determined that there is a possibility that the vehicle may come into contact with an obstacle ahead of the vehicle, as in the automatic braking device for a vehicle disclosed in Japanese Patent Laid-Open No. 5-240074, the shift gear position is set. There has been proposed a configuration in which the engine output is adjusted accordingly to smoothly operate the engine brake to reduce shock.

[0005]

However, although reducing the deceleration shock in this way can prevent a sudden acceleration step, the driver intends to decelerate by recognizing an obstacle or driving. Regardless of the fact that the intention is not reflected, for example, when the vehicle is ahead, even if the driver does not recognize it as an obstacle, if it is judged as an obstacle by the automatic braking control, The vehicle decelerates even though the driver does not intend to decelerate, which may cause the driver to feel uncomfortable.

The present invention has been made in view of the above-mentioned problems of the prior art, and automatically and optimally sets the vehicle driving force characteristics such as engine braking according to the front situation of the vehicle and the driver's intention. It is an object of the present invention to provide a vehicle driving force control device that enables comfortable running that sufficiently reflects the driver's intention, which corresponds to the driver's accelerator operation.

[0007]

According to a first aspect of the present invention, in a vehicle driving force control device, a distance detecting means for detecting a distance between a vehicle and a front object, and a distance detected by the distance detecting means are small. The obstacle judgment means for judging that there is an obstacle ahead of the host vehicle, the accelerator release judgment means for judging that the driver has released the accelerator pedal, and the moment of judgment by the obstacle judgment means. A time difference measuring means for measuring a time difference from the moment of judgment by the accelerator release judging means, and an automatic deceleration force generating means for automatically generating a deceleration force stronger than usual when the time difference is within a predetermined value, It is characterized by having.

In a second aspect based on the first aspect, the automatic deceleration force generating means operates on a lower speed side than a normal time from when it is determined that the time difference is within a predetermined value until a predetermined time elapses. It is characterized by generating a stronger engine brake than usual by selecting a gear ratio.

In a third aspect based on the first aspect, the automatic deceleration force generating means determines whether the time difference is within a predetermined value, a predetermined time has elapsed, or the driver releases the accelerator. The feature is that a deceleration force stronger than usual is generated until the operation is completed or whichever comes first.

In a fourth aspect based on the first aspect, the automatic deceleration force generating means cancels the deceleration control when the driver's braking operation is detected even if the time difference is within a predetermined time. Is characterized by.

In a fifth aspect based on the first to fourth aspects, the automatic deceleration force generating means has a time difference of about 2 to 3.
The feature is that the deceleration force is automatically generated when it is determined to be within the second.

In a sixth aspect based on the first to fifth aspects, the obstacle determining means increases the vehicle speed by the vehicle speed detecting means for detecting the speed of the own vehicle and the distance detected by the distance detecting means. An obstacle determination permitting unit that permits obstacle determination when the distance is smaller than a predetermined predetermined distance, and determines that an obstacle exists in front of the vehicle only when the obstacle determination is permitted. Is characterized by.

In a seventh aspect based on the first to sixth aspects, the obstacle determining means is arranged so that when the speed of decrease of the distance detected by the distance detecting means exceeds a predetermined value, the obstacle is ahead of the host vehicle. Is determined to exist.

In an eighth aspect based on the first to seventh aspects, the automatic deceleration force generating means includes a brake actuator that can be controlled independently of a driver's brake operating means, and the time difference is a predetermined value. It is characterized in that the brake actuator generates a deceleration force stronger than the normal engine brake from the time it is determined to be within the range until the driver's brake operation is detected.

[0015]

According to the first aspect of the present invention, the vehicle driving force control device uses the distance detecting means such as a laser radar transmitter and a reflected wave receiver mounted in front of the vehicle for the relative distance between the vehicle and the front object. When the detected relative distance becomes small, it is determined that an object in front of the own vehicle is approaching the own vehicle, and it is determined that an obstacle exists in front of the own vehicle. For example, when another vehicle suddenly cuts in front of the host vehicle, it is determined that the relative distance to the front object becomes smaller.

At this time, when the driver notices the presence of an obstacle in front of his own vehicle, most drivers operate to release the accelerator pedal that he had stepped on until then. When the accelerator pedal is released when an existing obstacle is noticed, the vehicle is required to have a deceleration force larger than usual, unlike in the case of a normal accelerator return operation or release operation.

Therefore, when the timing at which the accelerator pedal is released and the timing at which the obstacle is determined are close to each other, it is determined that the driver is requesting the vehicle to have a deceleration force larger than usual, and the vehicle is stronger than usual. By operating the engine brake or the like, it is possible to accurately assist the deceleration request in accordance with the driver's intention.

According to the second aspect of the invention, after a predetermined time elapses after it is determined that the driver's accelerator release operation is an operation based on the recognition of an object ahead of the vehicle as an obstacle, the driver is positively moved toward the low speed side. It is possible to end the engine braking and shift to normal running.

As a result, even when the driver recognizes an obstacle and shifts to normal running while releasing the accelerator, the strong engine brake is temporarily activated immediately after the driver releases the accelerator pedal. Since the minimum necessary engine braking is generated, it is possible to further generate deceleration force that reflects the driver's intention.

According to the third aspect of the invention, the driver's accelerator release operation is determined to be an operation based on the fact that the front object of the vehicle is recognized as an obstacle, and thereafter, during a predetermined time during which a deceleration force stronger than usual is activated. When the driver operates the accelerator pedal again, the generation of deceleration force such as aggressive engine braking to the low speed side can be immediately terminated.

Thus, when the driver recognizes the obstacle once, but immediately recognizes that the driver does not demand the vehicle to perform a particularly strong deceleration, he / she can follow the driver's intention. Since the deceleration can be immediately released and the normal running can be resumed, it is possible to reflect the driver's intention more comfortably.

According to the fourth aspect of the invention, the driver's accelerator release operation is determined to be an operation based on the recognition of an object in front of the vehicle as an obstacle, and thereafter, during a predetermined time during which a deceleration force stronger than usual is activated. , When the driver operates the brake pedal,
Generation of deceleration force such as aggressive engine braking to the low speed side can be immediately terminated.

As a result, even during automatic deceleration control,
When the driver depresses the brake pedal to perform the deceleration operation, it is determined that it is not necessary to further assist the deceleration, and the deceleration action is immediately released, so that the driver can have a natural deceleration characteristic. .

According to the fifth aspect of the invention, a human obstacle of 2 to 3 seconds is used as a criterion for judging whether or not the driver's accelerator release operation is an operation based on the recognition of an object ahead of the vehicle as an obstacle. A judgment standard close to the recognition standard is set.

As a result, it becomes possible to more accurately determine the deceleration intention request. For example, in the case where the accelerator is returned 4 to 5 seconds after the front vehicle interrupts, it is determined that the operation is not based on the recognition of the front vehicle as an obstacle. There is an effect that it is possible to avoid sudden deceleration against the intention.

According to the sixth aspect of the invention, when the vehicle speed of the own vehicle is high, even an object farther away from the own vehicle is judged to be an obstacle than when the vehicle speed is low. . The distance that is recognized as an obstacle increases as the vehicle speed increases, which increases safety.On the other hand, when the vehicle speed is low, a nearby object can be the target of the obstacle. Is possible. For example, while driving at low speed, it is possible to avoid sudden deceleration due to the deceleration of a distant front vehicle that does not feel like an obstacle for humans, and generate an appropriate deceleration force that better matches the driving intention. It becomes possible to do.

According to the seventh aspect of the invention, when the other vehicle interrupts in front of the own vehicle as compared with the case where the vehicle approaches the front vehicle gently, in most cases, the driver demands stronger engine braking than usual. By limiting the obstacle determination to such a case where the relative distance to the object in front of the own vehicle becomes abrupt, the driver's intention to decelerate can be surely grasped.

As a result, while avoiding the sudden generation of a decelerating force stronger than usual, a strong engine brake is generated as needed, and when another vehicle suddenly cuts in front of the vehicle, driving is performed. Even if the driver just releases the accelerator, the deceleration force stronger than usual is generated and the driver's fear is alleviated.

According to the eighth aspect of the invention, the driver operates the brake in addition to the normal engine brake between the time when the driver recognizes an obstacle and releases the accelerator and the time when the brake is operated. It is possible to generate a stronger deceleration force along the line.

As a result, the braking force is automatically assisted even during the delay time until the obstacle is noticed and the accelerator is changed to the brake, so that the so-called idling distance can be shortened. Further, it is possible to cope with a situation where a strong deceleration force is required, which cannot be dealt with by normal engine braking.

[0031]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a schematic configuration of a vehicle driving force control device according to this embodiment. As shown in FIG. 1, the vehicle driving force control device according to the present embodiment is a distance detecting means 1 for detecting a distance between a host vehicle and a front object.
And an obstacle determining means 2 for determining that an obstacle is present in front of the vehicle due to a decrease in the distance detected by the distance detecting means, and an accelerator release for determining that the driver has released the accelerator pedal. The judging means 3 and the time difference measuring means 4 for measuring the time difference between the moment of judgment by the obstacle judging means and the moment of judgment by the accelerator release judging means.
And an automatic deceleration force generation means 5 for automatically generating a deceleration force stronger than usual when the time difference is within a predetermined value.

FIG. 2 is a schematic diagram showing the configuration of a vehicle to which the vehicle driving force control device according to the present embodiment is applied. The output of the engine 101 is output to the drive wheels via an automatic transmission 103 with a built-in torque converter. (Not shown).

An electronically controlled throttle valve 102, which is driven to open and close by a motor or the like, is installed in the intake passage of the engine 101, and the intake air amount of the engine 101 is adjusted according to the opening of the electronically controlled throttle valve 102. The output torque of the engine is controlled. The electronically controlled throttle valve 102 is operated by a control signal from a throttle control module (hereinafter TCM) 51.

Further, the TCM 51 has a power train
An opening signal indicating the opening of the electronically controlled throttle valve 102 is transmitted from the control module (hereinafter referred to as PCM) 50, and the TCM 51 converts this opening signal into a motor drive voltage and calculates the actual electronically controlled throttle valve 10.
The electronic control throttle 102 is feedback-controlled so that the opening degree 2 becomes the opening degree instruction signal from the PCM 50.

The PCM 50 has an accelerator pedal opening from the accelerator pedal opening sensor 105, a brake operating signal from the brake operating switch 106, a select range signal from the range selecting lever 107 of the automatic transmission, and an engine (not shown). Signals from a rotation speed sensor, an intake air amount sensor, etc. are input to control the fuel supply amount to the engine 101 and ignition timing, to control the gear position of the automatic transmission 103, and to control the brake actuator 104.
Brake hydraulic pressure control for each vehicle via.

On the other hand, a laser radar 111 which emits infrared rays and receives reflected waves is arranged at the front part of the vehicle to measure the distance to the object in front of the vehicle. The reception result of the laser radar 111 is the forward object distance calculation device 5
In step 3, it is processed as a distance to the object in front and transmitted to the external environment information processing module 52.

A GPS antenna 113 for receiving signals from satellites is arranged at the rear of the vehicle. The information obtained from the GPS antenna 113 is transmitted to the position information processing device 54 in order to grasp the current position of the vehicle.
The position information processing device 54 stores map information in which geographical attributes and the like have been incorporated in advance as a recording medium such as a CD-ROM. The information and the like are collected and transmitted to the external environment information processing module 52. Further, the signal from the position information processing device 54 is also displayed on the monitor 112 provided in the driver's seat.

The external environment information processing module 52 transmits a signal representing the current vehicle environment to the PCM 50 based on the signals input from the front object distance calculation device 53 and the position information processing device 54. Receiving this signal, the PCM 50 controls the output of the engine 101 and the shift of the automatic transmission 103. On the contrary, PCM50 is engine 1
Output torque information 01, gear position information of the automatic transmission 103, signals from the accelerator opening sensor 105, the brake operation switch 106, and the like.
Send to 2. In response to this signal, the external environment information processing module 52 may improve the determination accuracy of the external environment or infer the psychological state of the driver.

Next, the control of the vehicle driving force, which is an essential part of the present invention, will be described with reference to FIGS. 3 to 9.

FIG. 3 is a flowchart of a portion corresponding to the obstacle determining means in the vehicle driving force control system according to the present embodiment, which is executed in the external environment processing module 52 at a rate of one task every 10 msec.

First, in step S11, the relative distance LR between the front object and the host vehicle transmitted from the front object distance calculation device 53 to the external environment processing module 52 is calculated as the relative distance Dis.
Store in t.

In step S12, the relative distance Dist input in step S11 and 10 input in the previous task are input.
The difference from the relative distance o1dDist before msec is calculated to calculate the relative velocity Vcol with the front object. After that, the current Dist is stored in o1dDist for the next calculation.

In step S13, the magnitude of the relative velocity Vcol calculated in step S12 is determined, and when it is determined that Vcol is negative, that is, the distance to the front object is smaller than that in the previous task, step S13 is performed. S1
Go to 4 and judge that there is an obstacle in front of your vehicle, then Fc
Store 1 in ol.

On the other hand, when it is determined that Vcol is not negative, that is, the distance to the front object is larger or has not changed as compared with the time of the previous task, the process proceeds to step S15, and the front of the own vehicle. Store 0 in Fcol because it is determined that there is no obstacle.

In this way, by processing the flow shown in FIG. 3, when it is determined that there is an obstacle in front of the host vehicle, 1 is stored in Fcol, and conversely, there is an obstacle in front of the company. When it is determined that there is not, 0 is stored in Fcol.

Similar to FIG. 3, FIG. 4 is a flowchart showing another example of the portion corresponding to the obstacle determining means in the vehicle driving force control device, which can be replaced with the program shown in the flow of FIG. In the external environment information processing module 52 as in the flow of FIG.
It is executed at a rate of 1 task per ec. Note that the description of the processing common to that in FIG. 3 is omitted.

Step S16 is step S1 in FIG.
In the process arranged between 1 and the process of step S12,
Based on the relationship between the distance Dist to the front object and the vehicle speed VSP, it is determined whether or not the obstacle determination is permitted. For example, the determination is made from the map shown in FIG. 5, and the higher the vehicle speed, the larger the distance to the front object that can be used for the obstacle determination.

In other words, by processing this step S16, the obstacle determining means in and after step S12 executes the obstacle determining means only when the distance detected by the distance detecting means is smaller than the predetermined distance which is largely determined in association with the increase in vehicle speed. Obstacle determination will be allowed.

Next, step S17 shows a process that can be replaced with step S13 in FIG. Here, the relative speed Vcol to the front object is the predetermined relative speed Vw.
It is assumed that the distance to the front object is drastically reduced by becoming larger than aricomi, and only at this time, it is determined that there is an obstacle, and the process proceeds to step S14.

That is, when this step S17 is processed, it is determined that there is an obstacle ahead when the distance detected by the distance detecting means suddenly becomes small, such as when there is an interrupting vehicle ahead of the own vehicle. Will be.

By processing the flow shown in FIG. 4 in this way, 1 is stored in Fcol when it is determined that there is an obstacle in front of the vehicle as in the flow shown in FIG. Further, when it is determined that there is no obstacle in front of the company, 0 is stored in Fcol.

FIG. 6 is a flow chart of a portion corresponding to the accelerator release detecting means, the time difference measuring means, and the portion for determining the occurrence of automatic deceleration in the vehicle driving force control device, P
It is executed in the CM 50, for example, every 10 msec.

First, in step S21, the value of the deceleration force correction timer TMDECL is checked. If it is 0, it is determined that the deceleration force correction is not currently being performed, and the process proceeds to step S22.
On the other hand, the value of the deceleration force correction timer TMDECL is 0
If it is not, the deceleration force correction has already been executed, so
This routine is terminated because it is not necessary to determine the generation of the deceleration force again.

Steps S22 to S27 are a routine for measuring the elapsed time from the moment when the driver releases the accelerator pedal.

In step S22, it is determined from the idle switch signal whether or not the accelerator pedal is released. If it is determined that the accelerator is released, the process proceeds to step S24. On the other hand, when it is determined that the accelerator pedal is not released, step S23
Go to.

In step S23, o1dl is set as a condition for determining the moment of accelerator release in the next task.
OFF (accelerator pedal not open) is stored in DLE, and timer TMACCL is reset.

In step S24, it is determined whether the timer to be subtracted immediately after the accelerator is released is not 0. If it is not 0, it is determined that the elapsed time after the accelerator is released is being measured, and the process proceeds to step S25. On the other hand, when the timer is 0, the process proceeds to step 26.

In step S25, one is subtracted from the subtraction timer TMACCL in order to measure the elapsed time after the accelerator is released.

In step S26, it is determined from the contents of oldIDLE whether or not the accelerator pedal has been released one task before. If oldIDLE is OFF,
It is determined that the current task is the moment when the accelerator pedal is released, and the process proceeds to step S27. On the other hand, old
If IDLE is ON, it is determined that the accelerator pedal is continuously released from the previous time, and the process proceeds to step S28.

In step S27, the initial value TMACCINI is stored in the subtraction timer TMACCL in order to measure the elapsed time after the accelerator is released, and at the same time, oldIDLE is stored.
Is stored with accelerator release information ON for determining the accelerator pedal state in the next task, and the process proceeds to step S28. Here, the value of 250 is stored in TMACCINI, but by subtracting this value one by one every 10 msec, the timer becomes 0 in 2.5 seconds, and the moment the accelerator is released and the obstacle is detected. It becomes one of the values that defines the time difference of 2-3 seconds at the moment of.

Steps S28 to S33 are a routine for determining an obstacle in front of the vehicle and measuring the elapsed time from that moment.

In step S28, it is determined whether or not an obstacle ahead of the host vehicle is determined from the contents of Fcol stored when the flow of FIG. 3 or 4 is processed, and Fco
When l is 1 and it is determined that there is an obstacle in front of the host vehicle, the process proceeds to step S30.

On the other hand, if Fcol is 0 and it is determined that there is no obstacle in front of the host vehicle, the flow advances to step S29 to determine the obstacle in front of the host vehicle in the next task. As a condition of 0, 0 (no obstacle in front of the own vehicle) is stored in oldFcol, the timer TMCOL is reset, and this routine ends.

In step S30, it is determined whether or not the timer TMCOL for subtracting an obstacle ahead of the host vehicle is 0 immediately after the determination. When the timer TMCOL is not 0, it is assumed that the elapsed time after determining the obstacle ahead of the own vehicle is already being measured, the process proceeds to step S31, and one subtraction timer TMCOL is set to measure the elapsed time after the obstacle determination. Subtract. On the other hand, when the timer TMCOL is 0, the process proceeds to step S32.

In step S32, it is determined whether or not an obstacle has been determined one task before, based on the contents of oldFcol, and if oldFcol is 0, the current task is determined to be an obstacle ahead of the host vehicle. It is determined that it is the moment when the process is completed, and the process proceeds to step S33. On the other hand, when oldFcol is 1, it is determined that the obstacle has continued since the previous time, and this routine is ended.

In step S33, the initial value TMCOLINI is stored in the subtraction timer TMCOL to measure the elapsed time after the obstacle is determined, and at the same time, the obstacle determination for determining the obstacle in the next task is stored in oldFcol. The information 1 is stored and the process proceeds to step S34. Also, although the value of 230 is stored in TMCOLINI here, by subtracting this value one by one every 10 msec,
The timer becomes 0 in 2.3 seconds, which is one of the values defining the time difference of 2-3 seconds between the moment when the accelerator is released and the moment when the obstacle is detected.

In step S34, when the subtraction timer TMACCL for measuring the elapsed time after the accelerator release is not 0, it is determined that the obstacle determination timing and the accelerator release operation timing are close to each other within a predetermined time, and the step S34 is performed.
Proceed to 35. On the other hand, when TMACCL is 0, it is determined that the deceleration force correction is not necessary because the predetermined time has elapsed after the accelerator release determination, and the routine is ended.

In step S35, TMDECINI which defines a period for correcting the deceleration force to be stronger than usual is stored as the initial value of the subtraction timer TMDECL.

That is, by processing the flow shown in FIG. 6, the period for correcting the deceleration force stronger than usual is measured when the moment of obstacle judgment and the moment of accelerator release operation are within predetermined values. An initial value TMDECINI is stored in the deceleration force correction timer TMDECL.

FIG. 7 is a flowchart of a portion corresponding to the automatic deceleration force generating means in the vehicle driving force control device, which is executed in the PCM 50, for example, every 10 msec.

First, in step S41, the gear ratio is determined from the gear ratio map of the transmission from the relationship between the accelerator depression amount APS operated by the driver and the vehicle speed VSP.
An example of the gear ratio map is shown in FIG. In this example, the transmission is a continuously variable transmission, and the target input speed tNinp of the transmission is selected instead of the gear ratio.

In step S42, the value of the deceleration force correction timer TMDECL, which corresponds to whether or not the automatic deceleration force correction is determined to be necessary in the flow shown in FIG. 6, is determined,
When the value of this timer is 0, it is determined that the correction of the automatic deceleration force is not necessary, and the correction of steps S43 to S44 is skipped, the process proceeds to step S45, and a command is issued to the transmission so that the normal gear ratio is achieved. send. On the other hand, when the value of the timer is not 0, it is determined that the automatic deceleration force needs to be corrected, and the process proceeds to step S43.

In step S43, the deceleration force correction timer TMDECL for judging the automatic deceleration force generation is decremented by one.

In step S44, the target speed ratio is corrected to the low speed side so that the transmission selects the speed ratio lower than the normal speed in order to realize the automatic deceleration force generation. This is an example of a continuously variable transmission, and the correction input rotation Nenbr is added to the target input rotation speed tNinp so that the deceleration force by the engine brake becomes strong.

In step S45, a command is sent to the transmission so that the gear ratio becomes the target input speed tNinp.

That is, by processing the flow shown in FIG. 7, the value of the deceleration force correction timer TMDECL that is subtracted after it is determined that the moment of obstacle determination and the moment of accelerator release operation are within predetermined values. Until the speed reaches 0, select a speed ratio lower than normal, or in the case of a continuously variable transmission, make the input speed higher than that of the accelerator fully closed characteristic and make engine braking stronger than usual. Can occur.

Similar to FIG. 7, FIG. 9 is a flowchart showing another example of the portion corresponding to the automatic deceleration force generating means in the vehicle driving force control device, which can be replaced by the program shown in the flow of FIG. is there. Similar to the flow of FIG. 7, it is executed in the PCM 50, for example, every 10 msec.

In step S51, the brake operation of the driver is detected by the brake operation switch 106, and if the brake is already depressed, it is determined that the deceleration force correction is unnecessary, and the process proceeds to step S55. On the contrary, when the brake is not depressed, the process proceeds to step S52.

In step S52, the value of the deceleration force correction timer TMDECL corresponding to whether or not the automatic deceleration force correction is determined in FIG. 6 is determined, and the value of the deceleration force correction timer TMDECL is 0. If so, it is determined that the correction of the automatic deceleration force is unnecessary, and the process proceeds to step S55. On the contrary, when the value of the deceleration force correction timer TMDECL is not 0, the process proceeds to S54.

In step S53, the deceleration force correction timer TMDECL for judging the automatic deceleration force generation is decremented by one.

In step S54, BRKdec is stored in the braking force correction amount tBRK by the brake actuator 104 in order to realize automatic deceleration force generation, and the process proceeds to step S56.

In step S55, the braking force correction amount t
0 is stored in BRK, and the process proceeds to step S56.

In step S56, in response to the result of step S54 or step S55, the brake actuator 104 is instructed to output the braking force correction amount tBRK, and this routine ends.

That is, by processing the flow shown in FIG. 9, the value of the deceleration force correction timer TMDECL subtracted after it is determined that the moment of obstacle determination and the moment of accelerator release operation are within the predetermined values. Until 0 or until the driver operates the brake, the brake actuator 104 can generate a decelerating force stronger than that of the normal engine brake.

Next, the operation and effect of this embodiment will be described with reference to FIG.

FIG. 10 shows the effect of the automatic deceleration force control of the present invention in a time-dependent diagram of obstacle detection, accelerator opening, gear position, and acceleration. The effect of the conventional automatic deceleration force control is also shown for comparison with the conventional one.

According to this, in the conventional automatic deceleration force control, at the same time when the obstacle judging means judges an obstacle, the gear position is changed to the low speed side to enhance the engine braking effect and increase the deceleration force. I understand. However, in such control, the deceleration action is performed regardless of the driver's operation intention (here, the accelerator pedal operation),
Therefore, there is a high possibility that the deceleration force acts even though the driver does not intend to decelerate, and the driver feels uncomfortable. Further, although there is some time lag between when the driver releases the accelerator pedal after the obstacle is determined, at this time, the gear is changed to the low speed side gear while the accelerator pedal is being depressed, and therefore, as shown in FIG. As shown in (4), a rapid acceleration occurs until the accelerator pedal is released, and when the accelerator is released, a rapid deceleration occurs this time, which causes a problem that the driver feels awkward.

On the other hand, in the automatic deceleration force control of the present invention, the control is not performed only by the obstacle judging means judging the obstacle, but the accelerator release judging means is operated by the driver as shown in FIG. When it is determined that the gear has been released, that is, when it is determined that the driver intends to decelerate, the gear is changed to the low speed side gear, and the deceleration force is applied until a predetermined time elapses. Further, this automatic deceleration force control is performed when the moment of obstacle determination and the moment of accelerator release determination are close, and conversely, when the moment of obstacle determination and the moment of accelerator release determination are far apart, for example, If the accelerator pedal is released after a short time since the distance between the vehicle and the vehicle is shortened, it is determined that the operation is not based on the fact that the driver recognizes the preceding vehicle as an obstacle, and the automatic deceleration force control is not performed.

As described above, the automatic deceleration force control of the present invention closely corresponds to the driver's accelerator operation. Therefore, the deceleration action does not sufficiently reflect the driver's operation intention, and the driver feels uncomfortable. Less will be given.

It is assumed that the deceleration action is released after a predetermined time has passed. However, if the deceleration action is released even when the accelerator pedal is depressed again, the driver may request the vehicle to perform a particularly strong deceleration. However, if the driver recognizes that it was not and cancels the accelerator release operation, he / she can immediately resume normal driving.

Further, if the distance to the front object capable of making an obstacle judgment according to the vehicle speed is set to be large, the distance becomes closer to the obstacle judgment of humans, and the driver does not recognize it as an obstacle at low speed running. It is possible to avoid slowing down a distant vehicle. On the contrary, when traveling at a high speed, even a distant vehicle is determined to be an obstacle, so that safety can be improved.

Further, if the condition for the obstacle judgment is limited to the case where the relative distance to the object in front of the own vehicle becomes sharply small, the driver's intention of deceleration can be surely grasped. As a result, it is possible to prevent the deceleration force stronger than usual from being unexpectedly generated, and conversely, it is possible to reliably generate the strong deceleration force when there is an interrupting vehicle and a strong deceleration request is made.

Although it has been explained here that the generation of the deceleration force is changed to the low speed gear to enhance the engine braking effect, the brake is operated by the brake actuator in addition to the normal engine braking. A strong deceleration force may be generated. As a result, a strong deceleration force can be generated and dealt with even in situations where normal engine braking is insufficient.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a vehicle driving force control device according to the present embodiment.

FIG. 2 is a schematic diagram showing a configuration of a vehicle to which the vehicle driving force control device according to the present embodiment is applied.

FIG. 3 is a flowchart of a portion corresponding to obstacle determining means.

FIG. 4 is a flowchart of another example of a portion corresponding to obstacle determining means.

FIG. 5 is a map for determining whether to permit obstacle determination.

FIG. 6 is a flowchart of a portion corresponding to an accelerator release detecting unit, a time difference measuring unit, and a unit that determines whether automatic deceleration occurs.

FIG. 7 is a flowchart of a portion corresponding to automatic deceleration force generation means.

FIG. 8 is a transmission gear ratio map.

FIG. 9 is a flowchart of another example of a portion corresponding to automatic deceleration force generation means.

FIG. 10 is a schematic diagram showing the effect of the present invention.

[Explanation of symbols]

1 Distance detection means 2 Obstacle judgment means 3 Accelerator release determination means 4 hour difference measuring means 5 Automatic deceleration force generation means 50 PCM 52 External environment information processing module 53 Forward object distance calculation device 54 Position Information Processing Device 101 engine 102 Electronically controlled throttle valve 103 Automatic transmission 104 brake actuator 105 Accelerator position sensor 106 Brake operation switch

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI B60K 41/20 B60K 41/20 41/26 41/26 B60T 7/12 B60T 7/12 C F16H 59/04 F16H 59/04 59 / 60 59/60 G01C 3/06 G01C 3/06 A 21/00 21/00 A G08G 1/16 G08G 1/16 E (56) Reference JP-A-5-240074 (JP, A) JP-A-6 -111200 (JP, A) JP 3-943 (JP, A) JP 5-240075 (JP, A) JP 7-17390 (JP, A) JP 63-270242 (JP, A) ) JP 59-157 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B60K 41/00 301 F02D 29/02 F02D 29/02 341 B60K 41/04 B60K 41/20 B60K 41/26 B60T 7/12 F16H 59/04 F16H 59/60

Claims (8)

(57) [Claims] 1. A vehicle driving force control device for controlling a driving force of a vehicle, the distance detecting means detecting a distance between a vehicle and a front object, and the distance detected by the distance detecting means being small. Obstacle determination means for determining that there is an obstacle in front of the vehicle, accelerator release determination means for determining that the driver has released the accelerator pedal, and the moment of determination by the obstacle determination means. A time difference measuring means for measuring a time difference from the moment of judgment by the accelerator release judging means, and an automatic deceleration force generating means for automatically generating a strong deceleration force when the time difference is within a predetermined value. A characteristic vehicle drive force control device. 2. The automatic deceleration force generation means selects a gear ratio on a lower speed side than usual and is stronger than usual until a predetermined time elapses after it is determined that the time difference is within a predetermined value. The vehicle driving force control device according to claim 1, wherein engine braking is generated. 3. The automatic deceleration force generating means determines whether the predetermined time has elapsed after determining that the time difference is within a predetermined value, or the driver finishes the accelerator release operation, whichever is earlier. The vehicle driving force control device according to claim 1, wherein a deceleration force stronger than usual is generated only during the period. 4. The vehicle according to claim 1, wherein the automatic deceleration force generation means cancels the deceleration control when a driver's braking operation is detected even if the time difference is within a predetermined time. Driving force control device. 5. The automatic deceleration force generating means automatically generates a deceleration force stronger than usual when it is determined that the time difference is within about 2 to 3 seconds. The vehicle driving force control device according to any one of 4 above. 6. The obstacle judging means detects a vehicle speed of the host vehicle, and when the distance detected by the distance detecting means is smaller than a predetermined distance which is largely determined in association with an increase in the vehicle speed. 6. An obstacle determination permission unit that permits obstacle determination, and determines that an obstacle exists ahead of the own vehicle only when the obstacle determination is permitted. The vehicle driving force control device according to one. 7. The obstacle determining means determines that an obstacle is present in front of the own vehicle when the decrease speed of the distance detected by the distance detecting means exceeds a predetermined value. 7. The vehicle driving force control device according to any one of 6 to 6. 8. The automatic deceleration force generation means includes a brake actuator that can be controlled independently of the driver's brake operation means, and the driver's brake operation is performed after it is determined that the time difference is within a predetermined value. 8. A deceleration force stronger than that of a normal engine brake is generated by the brake actuator until the detection of "1" is detected.
The vehicle driving force control device described in any one of 1.