JP4627142B2 - Collision prevention control device - Google Patents

Description

The present invention relates to an automobile collision prevention control apparatus for detecting an obstacle ahead by a radar or the like and preventing a collision with the obstacle.

  Conventionally, a radar that uses radio waves, laser light, or ultrasonic waves is mounted on an automobile, and it collides with an oncoming vehicle from the front in the traveling direction, collides with a stationary object on the road or outside the road, and travels ahead There has been proposed a device that detects the risk of a collision with a preceding vehicle and prevents a collision. The risk of collision is determined by the distance to the target searched by the radar and the relative speed. It is determined that there is a danger of a collision when the distance is short and sufficient braking cannot be applied in the time until the collision determined from the relative speed.

  When performing deceleration operation on a running vehicle, it is not possible to apply sufficient braking only by braking the wheels, and it is necessary to use engine braking together. Prior art has been proposed in which the engine brake is used while the possibility of a collision is small, and the brakes for the wheels are also used when the possibility of a collision becomes large (see, for example, Patent Document 1). It has also been disclosed to use a lock-up clutch in an automatic transmission to enable engine braking. There has also been proposed a prior art that alerts the driver by intermittently changing the fastening force of the seat belt when the possibility of a collision is high (see, for example, Patent Document 2).

  In an automobile in which a throttle that restricts the passage of air supplied to the engine is digitized, a system has been proposed in which the electronic throttle is controlled to be closed to suppress the generation of torque from the engine and to avoid a collision. In addition, there has been proposed a method of notifying the driver of the danger using an alarm device such as a lamp or a buzzer when it is determined that there is a danger of a collision.

JP-A-5-240075 Japanese Utility Model Publication No. 6-71333

  A driver of a vehicle such as an automobile should be driving so as not to cause a collision risk while watching the front and surroundings while driving. A situation in which the radar detects a target and determines that there is a danger of a collision is likely to occur when attention is distracted, such as a driver falling asleep. In a system using an electronic throttle, in order to suppress the generation of torque when there is a danger of a collision, the vehicle stops acceleration and is decelerated by an engine brake, which is advantageous in avoiding a collision. However, a vehicle without an electronic throttle cannot use a system for automatically applying engine braking, and the introduction of this technology requires the installation of an electronic throttle, which increases the cost of the vehicle. In addition, if the electronic throttle is smoothly operated, it is not necessary to alert the driver of the vehicle, and there is a possibility that the state where the attention is distracted will continue. Even in the prior art of Patent Document 1, the attention to the driver is insufficient.

  If the danger is notified by a lamp or buzzer to prevent a collision, the driver's attention can be alerted. However, it is desirable that lamps and buzzers are not used for other purposes. This is because if it is used for other purposes, it gets used to the operation, and even if it operates when there is a danger of a collision, it cannot give sufficient attention. Therefore, in order to notify the danger with a lamp or a buzzer to prevent a collision, a dedicated part is required, which causes a problem that the cost of the vehicle increases. The prior art of Patent Document 2 also requires a mechanism for intermittently changing the fastening force of the seat belt.

An object of the present invention is to provide a collision prevention control apparatus capable of effectively performing collision prevention without adding dedicated parts or the like.

The present invention is an automobile collision prevention control device having a clutch capable of switching the driving force between the driving force transmission mechanism from the driving source to the driving shaft,
Acceleration demand to increase the vehicle speed is equal to or greater than a predetermined criterion, and, when the distance to the front obstacle ahead of the running direction is detected are probed it is less than the predetermined value, the driving force from the driving source to the drive shaft Clutch release control means for performing clutch release control for releasing the clutch so as not to transmit ;
When at least one of the braking operation by the driver and the acceleration operation by the driver is detected when the clutch is released by the clutch release control by the clutch release control means, the clutch engagement unit that engages the clutch is detected. a clutch engagement control means for engagement control, a collision prevention control device which comprises a.

The present invention, the clutch opening control means, wherein the acceleration request is equal to or higher than a predetermined reference, and Ri distances der less than the predetermined value until the front obstacle, further, when the vehicle speed is equal to or higher than a predetermined speed The clutch release control is performed.

In the present invention, the acceleration request is characterized acceleration operation der Rukoto by the driver.

In the present invention, the automobile is equipped with an automatic speed control device for controlling the vehicle speed,
The acceleration request is characterized requests der Rukoto acceleration from the automatic speed control unit.

In the present invention, the drive source is an engine having a fuel cut function of stopping fuel supply,
When the clutch engagement control unit performs the clutch engagement control, said a row cormorants fuel cut control means the fuel cut to the engine, when a state where the clutch is engaged by the clutch engagement control In addition, it further includes a fuel cut control means for controlling so as to release the clutch, restart the fuel supply and return from the fuel cut when a braking operation is performed by the driver. .

In the present invention, the drive source is an engine having a fuel cut function of stopping fuel supply,
When the clutch engagement control means performs the clutch engagement control, the fuel cut control means performs a fuel cut on the engine, and when the clutch is engaged by the clutch engagement control. When the vehicle speed drops below a predetermined value or when the engine rotation speed drops below a predetermined value , the clutch is released and the fuel supply is restarted to control the fuel cut to return from the fuel cut. Control means is further included .

In the present invention, the vehicle includes an anti-lock brake system that prevents a wheel from being locked during a sudden braking operation by a driver.
The clutch engagement control means, when the braking operation by the driver after the clutch opening control by the clutch opening control means is performed, is a sudden braking operation the braking operation is actuated the anti-lock braking system when the is characterized not to perform the clutch engagement control.

In the present invention, the automobile includes a transmission capable of changing a transmission gear ratio between a rotation speed of the drive source and a rotation speed of the drive shaft in the drive force transmission mechanism,
While the clutch opening control unit clutch by by the clutch opening control is open, the upshift inhibition control means for performing the speed ratio control for prohibiting the upshift to be smaller than at the start of the clutch opening control , Further including .

In the present invention, the automobile includes a transmission capable of switching a gear ratio between a rotation speed of the drive source and a rotation speed of the drive shaft in a plurality of stages in the drive force transmission mechanism.
During the clutch by the clutch engagement control by the clutch engagement control section is engaged, the speed ratio of the transmission, the distance to the previous SL before Symbol obstacle ahead, set in accordance with and vehicle speed It further includes gear ratio setting control means for performing such control .

In the present invention, the motor vehicle, the driving force transmission mechanism, the transmission ratio between the rotational speed of the drive shaft and the rotation speed of the driving source be capable of continuously changing the continuously variable transmission, the target gear includes a CVT shift control is that performed by the feedback of the position and the actual gear position,
While the clutch is engaged by the clutch engagement control by the clutch engagement control means, the feedback gain of the transmission ratio control by the feedback of the continuously variable transmission, the feedback gain change for normal control to vary with time control Control means is further included .

According to the present invention, the driving force transmission mechanism from the driving source to the drive shaft, a car intermittent driving force has a switchable clutch, when the distance to the front side obstacle is less than the predetermined value, the clutch Control to release the clutch is performed by the release control means so as not to transmit the driving force from the driving source to the driving shaft. By releasing the clutch, it is possible to prevent acceleration from approaching an obstacle, and if the driver performs an acceleration operation that depresses the accelerator pedal after falling asleep, etc., the driver will drive with a sound that increases the engine speed. Can call attention. In the case of an automobile having a clutch that can switch driving force intermittently, there is no need to add a special part or the like in order to notify the danger of collision, and collision can be effectively prevented.
In addition, when the driver performs a braking operation such as depressing the brake pedal, the clutch is released so that the drive source is used for braking and the engine is controlled when the drive source is an engine. A power generation brake or the like when the brake or the drive source is an electric motor can be effectively used.
Even if an obstacle is detected and the clutch is released, if the driver indicates an intention to accelerate such as depressing the accelerator pedal, the release of the clutch is stopped and the clutch is engaged. When it is determined that acceleration is required, the vehicle can be accelerated according to the driver's intention.

According to the invention, the vehicle speed is equal to or greater than the predetermined value, the front obstacle distance less than the predetermined value has been detected, when a predetermined criterion or more acceleration request is detected, further closer to the front obstacle Since the risk of collision increases, it is possible to avoid an increase in the risk of collision by releasing the clutch so that the driving force from the drive source is not transmitted to the drive shaft.

Further, according to the present invention, when the acceleration operation by the driver is an acceleration request, and the acceleration request is equal to or greater than a predetermined reference, for example, when the driver depresses the accelerator pedal while falling asleep, the other vehicle if there is likely to collide with and obstacles, to release the clutch, avoiding the acceleration, it is possible to call attention of the driver at the sound of a driving source such as an engine.

Further, according to the present invention, if an automatic speed control device for controlling the vehicle speed, such as a cruise control system, is mounted on the vehicle, and there is a risk of collision even if a request for acceleration is issued from the automatic speed control device, the clutch by opening, it is possible not to perform acceleration. Attention is also drawn to the driver, and the driver can perform an operation such as stopping the automatic speed control device.

Further, according to the present invention, after fuel cut to stop fuel supply to the engine is performed and the engine brake is effectively applied, in order to avoid engine stop, fuel supply is resumed to return from the fuel cut. when performing the open clutch, it is possible to avoid the influence of the rotational speed increase of the engine.

According to the invention, after effectively engine braking is effected by performing a fuel cut to stop the fuel supply to the engine, when the vehicle speed is below a low to below the predetermined value, or the engine rotational speed to less than a predetermined value If you lower down, even to open the clutch I line returns from the fuel cut to avoid stalling the engine, the vehicle speed is sufficiently reduced, even if not as effective engine brake, provide the braking effect Can be small.

According to the invention, after the control to open the clutch, at the time of sudden braking operation an antilock brake system operates, and controls so as not to engage the clutch, that engine by sudden braking is prevented from stopping it can.

According to the present invention, the gear ratio of the rotational speed of the driving source and the rotational speed of the drive shaft in changeable transmission, while opening the clutch, smaller than at the beginning of the transmission ratio of the clutch opening control since it prohibits upshift to, after the clutch is engaged can effectively operate the engine brake.

Further, according to the present invention, a transmission capable of switching the speed ratio between the rotational speed of the drive source and the rotational speed of the drive shaft in a plurality of stages, and while disengaging the clutch , the distance to the front obstacle and the current since it is possible setting the gear ratio according to the vehicle speed, it is possible to engage the clutch after setting the gear ratio such as the engine brake works effectively.

According to the present invention, the gear ratio of the rotational speed of the drive shaft of the drive source continuously changeable continuously variable transmission, and engaging the clutch so as to utilize the driving source to the braking When controlling, the gear ratio of the transmission can be set according to the distance to the front obstacle and the current vehicle speed, so set the gain that enables fast shifting and use the engine brake Can be activated.

  FIG. 1 shows a schematic system configuration of a collision prevention apparatus 1 according to an embodiment of the present invention. The collision prevention apparatus 1 is mounted on the automobile 2. The automobile 2 travels by driving the drive wheels 5 and 6 through the automatic transmission 4 using a torque generator such as an engine or a motor as a drive source. The torque generator 3 outputs a rotational driving force from the output shaft 7. The automatic transmission 4 includes a clutch 8 and a transmission 9. The clutch 8 is interposed between the output shaft 7 and the transmission 9 and switches between a connected state in which the rotational driving force from the output shaft 7 is transmitted to the transmission 9 and a disconnected state in which the rotational drive force is not transmitted to the transmission 9. It is possible. The connection state and the disconnection state are not switched intermittently, but a half-clutch transition state by a fluid type torque converter or the like is provided in the middle, so that continuous and smooth switching is performed. Further, when a fluid torque converter or the like is provided, a lock-up clutch as shown in Patent Document 1 is used, and a state in which the output shaft 7 and the transmission 9 are directly connected is also possible. Become. Further, even if the transmission 9 called automatic MT or MMT is switched by manual operation, the clutch 8 can be controlled similarly.

The transmission 9 is a gear mechanism that can switch the gear ratio in a plurality of stages, and changes the rotational speed of the output shaft 7 and transmits it to the drive shaft 10. When the speed ratio is small , that is, when the rotational speed of the drive shaft 10 is larger than the rotational speed of the output shaft 7, the torque of the torque generator 3 output from the output shaft 7 is small for the drive shaft 10. Is transmitted. As the gear ratio in the transmission 9 increases , the torque transmitted to the drive shaft 10 increases. The rotational driving force transmitted to the drive shaft 10 is changed in direction by the differential 11 and rotationally drives the drive axle 12. Drive wheels 5 and 6 are mounted on both ends of the drive axle 12, respectively, and can be rotated by a rotational driving force to drive the automobile 2. The differential 11 is a differential mechanism that can drive the drive axle 12 independently on the drive wheels 5 and 6 side, and that the rotational speed is different between the inner ring side and the outer ring side when passing through a curved road. You can also. Further, the number of drive wheels 5 and 6 and drive axles 12 can be increased.

  The collision prevention apparatus 1 includes a radar 13 and a control means 14. The radar 13 radiates a radio wave of 30 GHz to 300 GHz called a millimeter wave with a wavelength of 10 mm to 1 mm, for example, receives a reflected wave from the target, and a radar device that detects the target and the radar device detects it. A radar ECU (Electro Control Unit) that recognizes the target and calculates the distance to the target and the relative speed. A radar apparatus may use radio waves in a frequency band called a centimeter wave having a wavelength longer than that of a millimeter wave. As a form of a radar apparatus using a radio wave, an FM-CW (Frequency Modulation-Continuous Wave) system, a pulse system, an SS (Spectrum Spread) system, or the like is used. Radio waves are radiated from the antenna. When exploring to a long distance, sharpen the directional characteristics of the antenna so that the beam does not spread, and scan to change the direction of the antenna to widen the exploration range. . When the exploration range is a short distance, the range in which radio waves are emitted is widened so that the target can be detected in a wide range. A radar device that uses ultrasonic waves or laser light instead of radio waves can also be used.

When the radar 13 detects an obstacle or the like, information such as the distance to the obstacle and the relative speed is given to the control means 14. The control means 14 is an embodiment of a clutch disengagement control means, a clutch engagement control means, a fuel cut control means, an upshift shift prohibition control means, a gear ratio setting control means, and a feedback gain change control means according to the present invention. The control means 14 is realized by a power train ECU that controls the power train of the automatic transmission 4 or the like, and controls the operation of the clutch 8 and the transmission 9 of the automatic transmission 4. Signals from the accelerator pedal opening, the brake pedal SW, the ABS / cruise controller, and the like are also input to the control means 14. A signal corresponding to the vehicle speed detected by the vehicle speed sensor 15 is also input to the control means 14. The accelerator pedal opening degree corresponds to the amount of depression of the accelerator pedal by the driver, and represents that the driver is performing a driving operation to decelerate by depressing the accelerator pedal. The brake pedal SW is a switch (SW) that is normally in an OFF state and is turned on when the driver steps on the brake pedal. ABS is an abbreviation for Antilock Brake System, and is a system that automatically controls the braking force so that the wheels do not lock when the driver performs a sudden braking operation. The cruise controller automatically controls the vehicle speed so that the automobile 2 travels at a constant speed.

  As described above, the collision preventing apparatus 1 according to the present embodiment is a clutch that can switch driving force to the automatic transmission 4 that is a driving force transmission mechanism from the torque generator 3 that is a driving source to the driving shaft 10. 8 is mounted on the automobile 2. The radar 13 functions as a distance detection unit that searches forward in the traveling direction and detects the distance to the obstacle ahead. When the distance to the front obstacle detected by the radar 13 is less than a predetermined value, the control unit 14 disconnects the clutch 8 so as not to transmit the driving force from the torque generator 3 as a driving source to the driving shaft 10. Control. When the clutch 8 is disengaged, the transmission of the driving force to the drive shaft 10 is stopped, so that it is possible to prevent the situation where the clutch 8 is accelerated so as to approach the obstacle. Even if the driver falls asleep and performs an acceleration operation that depresses the accelerator pedal, the vehicle speed does not increase, and the rotational speed of the torque generator 3 with a reduced load increases. Can be aroused. In the case of the automobile 2 including the clutch 8 capable of switching the driving force, there is no need to add a special part or the like to notify the danger of the collision, and the collision can be effectively prevented.

  FIG. 2 shows a schematic control procedure by the control means 14 of the collision prevention apparatus 1 of FIG. The control means 14 performs a control operation as a power train ECU that controls the automatic transmission 4 in accordance with a preset program. The control procedure shown in FIG. 2 is activated when the vehicle speed becomes, for example, a predetermined speed or more in the middle of the basic control procedure as the power train ECU. It can also be started at short time intervals by an interrupt process by a timer. Further, when the target is recognized by the radar 13, it can be activated as an interrupt process.

  When the control procedure is started, in step a1, it is determined whether or not the distance to the front obstacle detected by the radar 13 is less than a predetermined value. The predetermined value of this distance is about several tens of meters, for example. When it is determined in step a1 that the distance to the obstacle is less than a predetermined value, it is determined in step a2 whether or not the accelerator pedal opening is greater than or equal to a predetermined value. If the accelerator pedal opening is equal to or greater than the predetermined value, the process proceeds to step a3. This condition corresponds to a state in which the driver is stepping on the accelerator pedal even though the distance to the front obstacle is less than a predetermined value and there is a danger of a collision. Such a state is a state in which the driver is not aware that a front obstacle is approaching due to, for example, a snooze or a sidewalk, and has erroneously operated an acceleration request and should determine that there is a risk of a collision. is there.

  In step a3, control is performed to release the clutch 8 and cut off transmission of the driving force between the output shaft 7 and the transmission 9. By controlling the release of the clutch 8, the rotational driving force and torque generated from the torque generator 3 are disconnected and transmitted to the drive wheels 5 and 6, and the acceleration of the automobile 2 is stopped. Since the load on the torque generator 3 is reduced, the rotational speed increases. When the rotational speed of the torque generator 3 increases, the frequency of the sound generated from the torque generator 3 increases and the volume also increases. Such increasing sound serves as an alarm for the driver and can alert the driver.

  After the clutch release control is performed in step a3, the process proceeds to step a4. When the distance to the obstacle is greater than or equal to a predetermined value in step a1, or when the accelerator circuit is less than the predetermined value in step a2, the process skips step a3 and proceeds to step a4. In step a4, it is determined whether or not clutch release control is being performed. If the clutch release control is being performed, it is determined in step a5 whether the clutch opening is less than a predetermined value or whether the brake pedal SW is ON. When the condition is satisfied, it is determined that the driver has noticed the approach of the front obstacle by loosening the accelerator pedal, or further depressing the brake pedal, and further pushing the brake pedal, by arousing attention by the clutch release control. Move. In step a6, clutch engagement control for engaging the clutch 8 and connecting the torque transmission path is performed. When the clutch 8 is engaged and the torque transmission path is connected, a load is applied to the torque generator 3. If the torque generator 3 is in an operation state in which torque generation is suppressed, the torque generator 3 becomes a load on the drive wheels 5 and 6 side and can be used as a braking force such as engine brake. If the torque generator 3 is a motor, it functions as a generator and operates as a power generation brake. After the clutch engagement control in step a6, engine brake control is performed in step a7. In the engine brake control in step a7, a fuel supply stop control called fuel cut is performed so that the rotational speed of the engine decreases.

  After the engine brake control in step a7, the process proceeds to step a8. When it is determined in step a4 that clutch release control is not being performed, or when it is determined in step a5 that the accelerator opening is not less than the predetermined value, step a6 and step a7 are skipped and the process proceeds to step a8. In step a8, it is determined whether clutch engagement control is being performed. However, this clutch engagement control means that after the clutch release control at step a3, control is performed to engage the clutch 8 at step a6. Therefore, if the clutch release control is not performed, even if the clutch 8 is in the engaged state, the determination in step a8 is not in the clutch engagement control. If clutch engagement control is being performed, it is determined in step a9 whether or not fuel cut has been returned. When it is determined that the fuel cut has been returned, the clutch release control is performed in step a10, and then the fuel cut return control is performed in step a11.

  After step a11, the control procedure is temporarily terminated. When it is determined in step a8 that clutch engagement control is not being performed, or when it is determined in step a9 that fuel cut recovery is not performed, the control procedure is temporarily terminated. Even if the control procedure is once ended, if the state where the vehicle speed is equal to or higher than the predetermined speed continues, the control procedure from step a1 is repeated. Further, when the control procedure is started by the interrupt processing by the timer or when the control procedure is started by the target detection interrupt processing by the radar 13, if the condition is satisfied, the control procedure after step a1 is repeated as the interrupt processing. . However, for example, when both the conditions of step a1 and step a2 are not satisfied, the clutch release control of step a3 is not performed, and the determination at step a4 and step a8 is NO, and virtually nothing is performed. .

  That is, when the engine having a fuel cut function for stopping the fuel supply is the torque generating device 3 as a drive source, the control means 14 performs the engine brake in step a7 after the engagement control for connecting the clutch 8. Since fuel cut is performed on the engine during control, the engine brake can be effectively applied. If the detection of the braking request by the control means 14 as the braking request detecting means continues, the fuel cut state continues, the engine rotational speed decreases, and the engine may stop. When returning from the fuel cut in order to avoid stopping the engine, the rotational speed of the engine increases, and the vehicle speed is increased so as not to stop against the state where the vehicle is about to stop by braking. Since the clutch release control for disengaging the clutch 8 is performed and then the fuel supply is resumed and the control is resumed from the fuel cut, it is possible to avoid the influence of an increase in the rotational speed of the engine.

  Note that, in step 9, the condition for determining whether or not the control means 14 performs control so as to return from the fuel cut is that the vehicle speed is reduced to less than a predetermined value or the engine speed that is the torque generator 3 is The reduction is made to be less than a predetermined value. If the vehicle speed falls below a predetermined value, the effect on braking can be reduced even if the clutch 8 is disengaged when the recovery from the fuel cut is performed and the engine brake becomes ineffective. If the engine speed decreases below a predetermined value, the vehicle speed also decreases with the clutch 8 connected, and the engine brake becomes ineffective when the clutch is disconnected when returning from the fuel cut. However, the influence on braking can be reduced.

  When the vehicle starts when the vehicle speed reaches a predetermined speed as in the control procedure described above, the collision prevention apparatus 1 detects vehicle speed detecting means for detecting the vehicle speed and acceleration request detecting means for detecting an acceleration request for increasing the vehicle speed. And further including. The vehicle speed detection means is, for example, a vehicle speed sensor 15, and when the ABS is mounted, the rotation speed for each wheel is detected. The vehicle speed may be detected by the rotational speed of the drive shaft 10 or the drive axle 12. The acceleration request detection means is realized as a part of the function of the control means 14. The control means 14 is such that the vehicle speed detected by the vehicle speed sensor 15 or the like is equal to or higher than a predetermined speed, the acceleration request detected by the acceleration request detection means is higher than a predetermined reference, and the front detected by the radar 13 as the distance detection means. Control is performed to disengage the clutch 8 when the distance to the obstacle is less than a predetermined value. Even if the vehicle speed is greater than or equal to a predetermined value and a front obstacle is detected at a distance less than the predetermined value, if an acceleration request exceeding the predetermined standard is detected, there is a risk of a collision due to further proximity to the front obstacle Therefore, the clutch 8 is disengaged so that the driving force from the torque generator 3 that is a driving source is not transmitted to the driving shaft 10, thereby avoiding an increased risk of collision.

  In step a2 and step a5, the control means 14 functions as an acceleration request detection means, and detects an acceleration operation such as depression of an accelerator pedal by the driver as an acceleration request. In step a2 and step a5, the predetermined accelerator opening value may be the same, and with a hysteresis, the predetermined accelerator opening value in step a2 is larger than the predetermined accelerator opening value in step a5. In step a5, it can be clearly determined that the driver is depressing the accelerator pedal. That is, in step a2, since the acceleration operation by the driver is detected as an acceleration request, for example, when the driver steps on the accelerator pedal while sleeping, there is a possibility of colliding with another vehicle or an obstacle. If there is, the clutch 8 is disengaged by the clutch release control in step a3, acceleration can be avoided, and the driver's attention can be alerted by the sound of the driving source such as the engine.

  However, when it is determined in step a5 that the accelerator opening is not less than the predetermined value, that is, the accelerator opening is greater than or equal to the predetermined value, the control means 14 can also shift to the clutch engagement control in step a6. . After performing clutch release control for disengaging the clutch 8 so that the driving force is not transmitted from the torque generator 3 to the drive shaft 10 in step a3, the control means 14 as the acceleration request detection means detects the acceleration operation by the driver. It is because it is thought that it will judge. For example, in order to avoid a rear-end collision, the driver's intention may continue to accelerate even if there is an obstacle ahead, and the front obstacle may be avoided by a steering operation. Since the control means 14 stops the disconnection of the clutch 8 and controls the clutch 8 to be connected, the vehicle can be accelerated when an acceleration operation is performed with the driver's intention. When such control is performed, in the determination of the accelerator opening in step a5, a predetermined accelerator opening value serving as a reference for comparison is provided in two stages, and the smaller predetermined accelerator opening value is accelerated by the driver. A determination criterion for the suppression operation may be used, and the larger accelerator opening predetermined value may be the determination criterion for the acceleration operation by the driver. Even if an obstacle is detected and the clutch 8 is disengaged, if the driver shows an intention to accelerate such that the accelerator pedal is depressed, the disengagement of the clutch 8 is stopped and the clutch 8 is connected. When it is determined that acceleration is required, the vehicle can be accelerated according to the driver's intention.

  Although whether or not the accelerator opening in step a2 is greater than or equal to a predetermined value is a determination of whether or not there is an acceleration request by the driver, since the vehicle 2 is equipped with a cruise control system, the control means 14 It can also function as an acceleration request detecting means for detecting a request for acceleration from an automatic speed control device that controls the vehicle speed as an acceleration request and performing clutch release control in step a3. The control means 14 serving as an acceleration request detecting means can also disengage the clutch 8 so as not to accelerate the acceleration request that is automatically generated if there is a risk of collision. Attention is also drawn to the driver, and the driver can perform an operation such as stopping the automatic speed control device.

  In step a5, the control unit 14 functions as a braking request detection unit that detects an acceleration suppression operation by the driver as a braking request. That is, an operation in which the accelerator opening becomes smaller than a predetermined value, for example, by depressing the accelerator pedal, is determined to be an operation that suppresses acceleration indicating an intention to apply the engine brake, and the clutch engagement control in step a6 is performed. The clutch 8 once disengaged by the clutch release control in step a3 can be connected to enable the engine brake or the like.

  In Step a5, the brake pedal SW is turned on to detect the braking operation by the driver as a braking request. Therefore, the control unit 14 serves as a braking request detection unit that detects the braking operation by the driver as a braking request. Function. If the driver performs a braking operation such as depressing the brake pedal, the clutch 8 can be connected by the clutch engaging operation in step a6, and the engine brake can be used effectively.

  The acceleration suppression operation for relaxing the depression of the accelerator pedal as described above and the braking operation for depressing the brake pedal are operations for requesting braking by the driver. The operation of the braking request for reducing the vehicle speed is not only performed by the driver, but also when an automatic braking device such as an automatic braking system capable of performing braking for preventing a collision is mounted, the control means 14 Can function as a braking request detecting means for detecting a braking request from the automatic braking device. Since a braking request from an automatic braking system or the like is detected as a braking request, even when the braking is applied from the automatic braking device, the clutch 8 once disconnected by the clutch release control of step a3 is connected by the clutch engagement control of step a6. Thus, the engine brake or the like can be effectively used.

  For example, even when a motor is used as the torque generator 3 in a hybrid vehicle, a fuel cell vehicle, an electric vehicle, etc., if the clutch 8 is disconnected by the clutch release control in step a3, acceleration is stopped and the motor is stopped. The load on the vehicle is reduced and the rotational speed increases, and the driver can be alerted with sound. When a braking request is detected after the clutch 8 is disengaged, the electric motor operates as a generator, and the clutch 8 is connected to control the motor to be used for braking. Can be used effectively.

  When the driver is alerted by the clutch release control in step a3 and the driver depresses the brake pedal rapidly and applies sudden braking, the tire is locked and slip occurs between the road surface and the braking distance is increased. There is a risk of becoming. If the ABS is mounted, it is possible to prevent the wheels from being locked during a sudden braking operation by the driver. However, if this sudden braking operation is determined as the brake pedal SW in the ON state at step a5, and the clutch engagement control is performed at step a6 and the clutch 8 is connected, the vehicle automatically prevents the wheels from locking. However, there is a risk that the engine will stop with braking. In the case where an ABS is provided, it is preferable to skip step a6 and step a7 if the ABS operates even if the condition is satisfied in the determination in step a5. The control means 14 controls the clutch 8 not to be connected at the time of a sudden braking operation in which an anti-lock brake system such as ABS is operated after the control to disengage the clutch 8. Can be avoided.

  After performing the clutch release control in step a3, the control means 14 starts the clutch release control by the clutch release control while the clutch 8 is disconnected until the clutch engagement control is performed in step a6. It is preferable to prohibit the upshift to be greater than the time. The driving force transmission mechanism of the automobile 2 in FIG. 1 includes a transmission 9 that can change the speed ratio between the rotational speed of the torque generator 3 as a driving source and the rotational speed of the drive shaft 10. Control such as switching of the gear ratio is performed by a certain power train ECU. In an upshift that increases the gear ratio, the torque to be transmitted becomes small, and the engine brake cannot be used effectively. Since the control means 14 prohibits an upshift to increase the gear ratio larger than that at the start of clutch disengagement control while the clutch 8 is disengaged, the gear ratio at which the engine brake is effective after the clutch 8 is connected. The engine brake can be operated effectively.

  Further, while the clutch 8 is disengaged, the transmission ratio of the transmission 9 is detected by the distance to the front obstacle detected by the distance detecting means that is the radar 13 and by the vehicle speed detecting means such as the vehicle speed sensor 15. It can also be set according to the current vehicle speed. The control means 14 sets the gear ratio of the transmission 9 according to the distance to the front obstacle and the current vehicle speed when controlling the torque generator 3 to be used for braking by connecting the clutch 8. Therefore, if the clutch 8 is connected, the torque generator 3 and the drive shaft 10 are connected at an appropriate speed ratio, and braking such as engine braking can be used effectively.

  As the automatic transmission 4, a continuously variable transmission such as CVT capable of continuously changing the speed ratio between the rotational speed of the torque generator 3 and the rotational speed of the drive shaft 10 can be used as the transmission 9. The control means 14 for controlling the continuously variable transmission is a forward obstacle that detects the speed ratio of the transmission by the distance detecting means when the clutch 8 is connected to control the torque generator 3 to be used for braking. Can be set according to the distance to the vehicle and the current vehicle speed detected by the vehicle speed detection means, and therefore, the use of the engine brake can be made effective by setting a gain that enables a fast shift.

  Furthermore, since the determination of the accelerator opening in step a2 is a determination as to whether or not the driver is likely to fall asleep or look aside, it is possible to capture the state of a nap or the like with a camera or the like that captures the driver. If the image data is directly detected and a drowsy driving is detected, the clutch 8 may be disconnected by the clutch release control in step a3.

1 is a block diagram showing a schematic system configuration of a collision prevention apparatus 1 according to an embodiment of the present invention. It is a flowchart which shows the schematic control procedure by the control means 9 of the collision prevention apparatus 1 of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Collision prevention apparatus 2 Automobile 3 Torque generator 4 Automatic transmission 7 Output shaft 8 Clutch 9 Transmission 10 Drive shaft 13 Radar 14 Control means 15 Vehicle speed sensor

Claims (10)

A collision prevention control device for an automobile having a clutch capable of switching driving force to a driving force transmission mechanism from a driving source to a driving shaft,
Acceleration demand to increase the vehicle speed is equal to or greater than a predetermined criterion, and, when the distance to the front obstacle ahead of the running direction is detected are probed it is less than the predetermined value, the driving force from the driving source to the drive shaft Clutch release control means for performing clutch release control for releasing the clutch so as not to transmit ;
When at least one of the braking operation by the driver and the acceleration operation by the driver is detected when the clutch is released by the clutch release control by the clutch release control means, the clutch engagement unit that engages the clutch is detected. collision prevention control device which comprises a clutch engagement control means for engagement control, the. The clutch opening control means, wherein the acceleration request is greater than or equal to a predetermined criterion, and the distance to the obstacle ahead Ri der less than the predetermined value, further, when the vehicle speed is equal to or higher than a predetermined speed, the clutch opening control The collision prevention control device according to claim 1, wherein: The acceleration request is the collision prevention control device according to claim 1 or 2, wherein the acceleration operation der Rukoto by the driver. The automobile is equipped with an automatic speed control device for controlling the vehicle speed,
The acceleration request is the collision prevention control device according to claim 1 or 2, wherein the request der Rukoto acceleration from the automatic speed control unit. The drive source is an engine having a fuel cut function for stopping fuel supply,
When the clutch engagement control unit performs the clutch engagement control, said a row cormorants fuel cut control means the fuel cut to the engine, when a state where the clutch is engaged by the clutch engagement control In addition, it further includes a fuel cut control means for controlling so as to release the clutch, restart the fuel supply and return from the fuel cut when a braking operation is performed by the driver. The collision prevention control device according to any one of claims 1 to 4 . The drive source is an engine having a fuel cut function for stopping fuel supply,
When the clutch engagement control means performs the clutch engagement control, the fuel cut control means performs a fuel cut on the engine, and when the clutch is engaged by the clutch engagement control. When the vehicle speed drops below a predetermined value or when the engine rotation speed drops below a predetermined value , the clutch is released and the fuel supply is restarted to control the fuel cut to return from the fuel cut. The collision prevention control device according to any one of claims 1 to 4 , further comprising a control means . The automobile includes an anti-lock brake system that prevents a wheel from being locked during a sudden braking operation by a driver.
The clutch engagement control means, when the braking operation by the driver after the clutch opening control by the clutch opening control means is performed, is a sudden braking operation the braking operation is actuated the anti-lock braking system when the collision prevention control device according to any one of claims 1 to 6, characterized in that does not perform the clutch engagement control. The automobile includes a transmission capable of changing a transmission gear ratio between a rotation speed of the drive source and a rotation speed of the drive shaft in the drive force transmission mechanism,
While the clutch opening control unit clutch by by the clutch opening control is open, the upshift inhibition control means for performing the speed ratio control for prohibiting the upshift to be smaller than at the start of the clutch opening control The collision prevention control device according to any one of claims 1 to 7 , further comprising : The automobile includes a transmission capable of switching a gear ratio between a rotation speed of the drive source and a rotation speed of the drive shaft in a plurality of stages in the driving force transmission mechanism,
During the clutch by the clutch engagement control by the clutch engagement control section is engaged, the speed ratio of the transmission, the distance to the previous SL before Symbol obstacle ahead, set in accordance with and vehicle speed The collision prevention control device according to any one of claims 1 to 7 , further comprising a transmission ratio setting control means for performing control . The automobile is a continuously variable transmission capable of continuously changing a transmission gear ratio between a rotational speed of the drive source and a rotational speed of the drive shaft to the driving force transmission mechanism , the target transmission position and the actual transmission position. includes a CVT shift control is that performed by the feedback and,
While the clutch is engaged by the clutch engagement control by the clutch engagement control means, the feedback gain of the transmission ratio control by the feedback of the continuously variable transmission, the feedback gain change for normal control to vary with time control The collision prevention control device according to any one of claims 1 to 7 , further comprising a control means .

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