JP5984379B2 - Vehicle control device - Google Patents

Description

  The present invention relates to a vehicle control device that automatically stops a drive source that generates a driving force such as an engine when a predetermined automatic stop condition is satisfied, and restarts the drive source when a predetermined restart condition is satisfied.

  Conventionally, a so-called idle stop vehicle starts an engine by an IG (ignition) on operation, and thereafter executes idle stop control until the engine stops by an IG off operation, and a predetermined automatic stop condition is satisfied. The engine is automatically stopped and the engine is automatically restarted when a predetermined restart condition is satisfied.

  In this kind of idle stop vehicle, it is practiced to mount a control technology corresponding to a collision with an obstacle such as a vehicle existing in front of the host vehicle (see, for example, paragraphs 0004-0006 of Patent Document 1). .

JP 2008-121583 A

  As such, when the presence of an obstacle in front of the host vehicle is detected and the possibility of collision with the obstacle is detected, the idle stop function in which the automatic stop condition is satisfied and the engine is stopped is activated. Even so, when approaching the minimum collision avoidance distance necessary to avoid a collision with an obstacle, the brake is automatically actuated and controlled to stop at the minimum collision avoidance distance within 1 m from the obstacle. A collision avoidance system can be considered. Here, according to the technical guidelines of the Ministry of Land, Infrastructure, Transport and Tourism, in order to prevent the driver from overconfidence with the collision avoidance system, the stopping distance is defined as 1 m or less from the obstacle.

  By the way, in the case of the collision avoidance system described above, a means for generating a creeping force that can be advanced without stepping on the accelerator pedal by a driving source such as an engine or a motor may be further mounted. As described above, when the vehicle further includes the creep force generation means, when the vehicle stops at a short distance within 1 m from the obstacle ahead by the operation of the automatic brake by the collision avoidance system, the driver mistakenly When the engine (or motor) restart condition is satisfied, for example, when the foot is released from the brake pedal, the vehicle that has stopped within 1m from the obstacle is moved forward by the creep force generated by the creep force generation means. You may go ahead and hit an obstacle.

  Thus, in a vehicle having an idle stop function equipped with a collision avoidance system and a means for generating a creep force, the driver does not intend when the idle stop function is activated and the vehicle is stopped by the operation of an automatic brake. Nevertheless, problems may arise due to the establishment of the engine (or motor) restart condition.

  The present invention relates to a vehicle having an idle stop function equipped with a collision avoidance system and a means for generating a creep force, in a state where the idle stop function is activated and stopped by the operation of an automatic brake. It is an object of the present invention to make it possible to avoid a collision with an obstacle in advance.

In order to achieve the above-described object, the vehicle control device of the present invention automatically stops the drive source that generates the driving force of the vehicle when the predetermined automatic stop condition is satisfied, and when the predetermined restart condition is satisfied, In the vehicle control device for restarting the drive source, a creep force generating means for generating a creep force by driving the drive source, a detection means for detecting a collision possibility with an obstacle, and a collision possible by the detection means Automatic brake means for operating an automatic brake to stop the vehicle at a collision avoidance distance necessary for avoiding a collision with the obstacle based on the presence of the presence of the obstacle, and during the automatic stop of the drive source during traveling wherein the operation start timing when actuating the automatic brake, automatic-stop of the driving source is switched to a timing earlier than when not in the automatic stop of the drive source The stopping distance by some the automatic braking of the case, characterized by comprising a switching means you longer than the stopping distance by said automatic braking when not in automatic stop of the drive source (Claim 1).

  According to the first aspect of the present invention, when the automatic stop condition of the drive source is established while the vehicle is running and the detection means detects the possibility of collision with the obstacle during the automatic stop of the drive source. The brake means is automatically operated by the automatic brake means so as to stop at a collision avoidance distance necessary for avoiding a collision with an obstacle, and the vehicle is forcibly stopped. At this time, during the automatic stop of the drive source during traveling, the operation start timing when the automatic brake is operated by the automatic brake means is switched by the switching means to an earlier timing than when the drive source is not automatically stopped, The vehicle stops at a long stop distance compared to the stop distance to the obstacle by the automatic brake when the drive source is not automatically stopped.

  For this reason, the stopping distance to obstacles due to automatic braking when the drive source is automatically stopped is longer than when the drive source is not automatically stopped. Therefore, even if the restart condition of the drive source is established and the vehicle advances in the direction that the vehicle should travel by the creep force generated by the creep force generation means, the driver notices the vehicle's progress until the vehicle collides with the obstacle. The brake can be operated.

  In this way, even in a vehicle with improved fuel efficiency that automatically stops the drive source during traveling, even if the vehicle is equipped with a creep force generating means and an automatic brake means, the drive source is restarted after stopping by the automatic brake. Collisions with obstacles due to creep force due to the conditions being satisfied can be avoided in advance.

It is a block diagram of one embodiment of a vehicle control device of the present invention applied to an idle stop vehicle. It is operation | movement explanatory drawing of the control apparatus for vehicles of FIG. It is operation | movement explanatory drawing of the control apparatus for vehicles of FIG. It is a flowchart for operation | movement description of the control apparatus for vehicles of FIG.

  Next, an embodiment of the present invention will be described with reference to FIGS. 1 is a block diagram of a vehicle control device provided in an idle stop vehicle, FIGS. 2 and 3 are operation explanatory diagrams, and FIG. 4 is a flowchart for explaining operations.

  As shown in FIG. 1, the idle stop vehicle 1 has one lead battery 2 having a relatively small capacity of 12 V as a power source in order to reduce weight, size, etc., and the negative terminal of the lead battery 2 is It is connected to the casing of the idle stop vehicle 1.

  The engine 3 of the idle stop vehicle 1 has a transmission-side CVT 4, and a torque converter (including a lock-up clutch mechanism) 5 is interposed between the CVT 4 and the engine 3.

  The engine 3 is started by a starter 6, and the starter 6 is supplied with power from the lead battery 2 via a relay 7 to generate a driving force for starting the engine 3. Further, the battery sensor 8 provided close to the lead battery 2 between the positive terminal of the lead battery 2 and the relay 7 detects the temperature and current of the lead battery 2, and the rotational force of the engine 3 causes the belt 10 to rotate. To the alternator 9, and the lead battery 2 is charged by the power generation output of the alternator 9 while the vehicle is running.

  Further, as shown in FIG. 1, the idle stop vehicle 1 is provided with an idle stop control unit 11 formed by an ECU for idle stop control, an engine control unit 12 formed by an ECU for engine control, and ABS (Antilocked Breaking). An ABS control unit 13 formed by a system control ECU, a CVT control unit 14 formed by a CVT (continuous variable transmission) control ECU, and a PCS control unit 15 formed by a PCS (Pre Crash Safety) control ECU are provided. These control units 11 to 15 are each formed by a microcomputer or the like, and exchange information via a communication bus 16 such as CAN.

  Further, as shown in FIG. 1, a vehicle speed sensor 18 that detects the vehicle speed and provides the vehicle speed information to the ABS control unit 13 is provided, and the hydraulic pressure that provides the ABS control unit 13 with detection information of the master cylinder pressure of the brake mechanism. A sensor 19 is provided, and a display unit 20 formed by a combination meter is provided on the dashboard. Various display data received via the communication bus 16 are displayed on the display unit 20.

  In the idle stop vehicle 1 described above, the driver depresses the brake pedal during traveling, and the idle stop control unit 11 performs a predetermined automatic stop condition (for example, a condition that the stop lamp is lit and the vehicle speed is equal to or lower than a predetermined vehicle speed, etc. ) Is confirmed, an engine stop command is output to the engine control unit 12 when the vehicle speed is reduced to a predetermined vehicle speed or less (for example, 7 km / h or less) even if the travel is not completely stopped. Stopped. Subsequently, in the automatic stop state, the driver removes his / her foot from the brake pedal, and the idle stop control unit 11 establishes a predetermined restart condition (for example, a condition that the stop lamp is turned off and the door is closed). If confirmed, the stopped engine 3 is automatically restarted.

  In addition, the engine control unit 12 has a creep force that allows the idle stop vehicle 1 to start in an idling state in which the engine 3 has reached a rotational speed indicating a complete explosion and neither the brake pedal nor the accelerator pedal is depressed. The engine 3 is controlled so as to generate the above, and the generation control of the creep force by the engine control unit 12 corresponds to the “creep force applying means” in the present invention.

  By the way, the PCS control unit 15 takes in a detection signal of a laser radar 17 that measures a distance from an obstacle such as a vehicle ahead of the host vehicle every predetermined time, and sends a vehicle speed sensor 18 via the ABS control unit 13 and the communication bus 16. The vehicle speed information of the own vehicle detected by the above is taken in, and whether or not there is a possibility of collision with the obstacle is detected based on the distance to the obstacle and the own vehicle speed. The function of detecting the possibility of collision with an obstacle by the PCS control unit 15 corresponds to the “detection means” in the present invention.

  Further, the ABS control unit 13 controls a brake hydraulic pressure control valve (for example, a solenoid valve) downstream of the master cylinder (not shown) at the time of a sudden brake operation by a driver or a brake operation on a low friction road, and brakes for each wheel. ABS control that controls the force to prevent sliding due to wheel locking is executed. Further, when the PCS control unit 15 detects that there is a possibility of collision with an obstacle such as a vehicle ahead, the PCS control unit 15 outputs an automatic brake command to the ABS control unit 13 and the obstacle. The ABS control unit 13 controls the brake hydraulic pressure control valve downstream of the master cylinder so that it stops at the minimum collision avoidance distance necessary for avoiding a collision with the driver, regardless of the operation of the brake pedal by the driver. The automatic brake operation control for automatically applying the brake is executed. Such a function of outputting an automatic brake command to the ABS control unit 13 by the PCS control unit 15 corresponds to a function as “automatic brake means” in the present invention.

  The idle stop operation of the idle stop vehicle 1 having such a configuration will be briefly described. When the driver commands an engine start by turning on an IG key (not shown), an IG on signal is transmitted to a communication bus, for example. 16 is input to the idle stop control unit 11, and based on this input, the idle stop control unit 11 energizes the relay 7 instantaneously to turn it on, and feeds the power of the lead battery 2 to the starter 6 to start the starter 6. Then, the stopped engine 3 is started (initial start). Once the engine 3 is started and the lead battery 2 is once fully charged with the power generated by the alternator 9, the idle stop control unit 11 is then idle stopped until the engine 3 is stopped by turning off the IG key. Execute control.

  The idle stop control unit 11 includes information on the engine control unit 12 (engine information such as engine speed and cooling water temperature), information on the current and temperature of the lead battery 2, and the ABS control unit via the communication bus 16. 13, information on the vehicle speed detected by the vehicle speed sensor 18, information on the master cylinder pressure by the hydraulic pressure sensor 19, lock-up clutch information of the CVT control unit 14, information on switches in various parts of the vehicle such as a stop lamp switch and a courtesy switch (not shown). Etc. are input.

  Based on this information, the idle stop control unit 11 during the idle stop control confirms that the driver depresses the brake pedal according to a red signal of the traffic signal and the like, and that the master cylinder pressure is equal to or higher than a predetermined depression pressure. When detected, by confirming the establishment of a predetermined automatic stop condition for idle stop control (for example, a condition that the stop lamp is lit and the vehicle speed is equal to or lower than the predetermined vehicle speed), the predetermined vehicle speed can be obtained even if the traveling is not completely stopped. If the speed falls below (for example, 7 km / h or less), an engine stop command is output to the engine control unit 12, and the engine control unit 12 throttles the fuel throttle to automatically stop the engine 3.

  Next, when it is detected that the driver has lifted his / her foot from the brake pedal and the master cylinder pressure has dropped to a predetermined release pressure, such as when the traffic signal changes to a green light, the idle stop vehicle 1 performs a predetermined restart of the idle stop control. By confirming that the condition (for example, the condition that the stop lamp is turned off and the door is closed) is satisfied, the idle stop control unit 11 instantaneously energizes the relay 7 to turn on the power of the lead battery 2. The starter 6 is powered to start the starter 6, and the stopped engine 3 is automatically restarted. Thereafter, automatic stop of the engine 3 based on establishment of a predetermined stop condition during deceleration and automatic restart of the engine 3 based on establishment of a predetermined restart condition are alternately performed.

  At this time, when the engine 3 is restarted, the engine speed information reaches the speed indicating complete explosion, the brake force returns to the original state changing according to the master cylinder pressure, and the accelerator pedal is not depressed. This is a so-called idling state, and even in this idling state, a creep force that allows the idle stop vehicle 1 to travel is generated by the engine 3 and the torque converter 5. Force generation control corresponds to “creep force generation means” in the present invention.

  Further, the above-described idle stop vehicle 1 is provided with a function of switching the operation start timing of the automatic brake. That is, when the idle stop control by the idle stop control unit 11 is executed by the PCS control unit 15 and the engine 3 is automatically stopped during traveling, the start timing of the automatic brake by the ABS control unit 13 is It is possible to switch to an earlier timing than when not automatically stopping. The switching function by the PCS control unit 15 corresponds to the “switching means” in the present invention.

  Here, when the engine 3 is not automatically stopped, for example, when the driver is not driving the brake pedal even though it should be stopped due to a red traffic light signal, This corresponds to the case where the brake pedal is depressed with a delay in noticing the red signal.

  In order to execute the switching control described above, it is preferable to experimentally determine how much it is best to advance the operation start timing of the automatic brake. That is, for each relative speed between the host vehicle and the obstacle, an automatic brake operation start distance with respect to the obstacle is obtained in advance and is mapped and stored in a predetermined memory or the like. At this time, the distance from the obstacle when the automatic brake is activated and stopped at the automatic brake activation start distance for each relative speed is the minimum collision avoidance distance necessary for avoiding the collision. As shown in FIG. 2, for example, the operation start time (horizontal axis) and the operation start distance (vertical axis) are inversely proportional to each other so as to stop at a distance longer than a predetermined collision avoidance distance. The switching pattern P may be experimentally derived in advance, and the switching pattern P may be stored in advance in a memory or the like and read when necessary. In addition, the “minimum collision avoidance distance necessary for avoiding a collision” may not be strictly the minimum necessary distance, and may be an obstacle due to a creep force after restarting a driving source such as an engine. The main point is that the distance is a possibility of collision.

  Then, as the operation start timing of the automatic brake by the ABS control unit 13 when the engine 3 is not automatically stopped without performing the idle stop control by the idle stop control unit 11, for example, the operation start distance in FIG. In the state where the operation start time is set to Ta in Sa, the idle start control by the idle stop control unit 11 is executed and the operation start timing of the automatic brake is advanced when the engine 3 is automatically stopped. Then, the operation start distance in FIG. 2 is switched to Sb (> Sa) and the operation start time is Tb (<Ta).

  As a result, when the operation start distance is set to Sa (operation start time = Ta) as the operation start timing of the automatic brake during the idle stop non-execution, as shown by the broken line in FIG. The idle stop vehicle 1 is stopped at the minimum collision avoidance distance D1 within 1 m, and the operation start distance is switched to Sb (operation start time = Tb) as the operation start timing of the automatic brake during the idle stop execution. In this case, as shown by a solid line in FIG. 3, the idle stop vehicle 1 is at a distance D2 (> D1) that is a predetermined distance (for example, 1 m) longer than the minimum collision avoidance distance D1. Stop.

  As a result, if the restart condition of the engine 3 is satisfied based on an erroneous operation in which the driver accidentally removes his / her foot from the brake pedal after the stop by the automatic brake, the above-described creep force is generated and the idle stop vehicle 1 is arbitrarily used. However, since there is a distance D2 that is longer than the minimum collision avoidance distance D1 by a predetermined amount between the idle stop vehicle 1 and the obstacle (the vehicle ahead), the driver stops the vehicle. It will be in a state where it can recognize the progress of the brake operation.

  Next, the operation of the automatic brake will be described with reference to the flowchart of FIG.

  As shown in FIG. 4, the PCS control unit 15 causes the host vehicle to detect the distance from the obstacle by the laser radar 17 and the vehicle speed information from the vehicle speed sensor 18 sent from the ABS control unit 13 via the communication bus 16. The current relative speed between the vehicle and the obstacle is derived, the automatic brake operation start distance corresponding to the derived relative speed is read from the memory (step S1), and then the idle stop control unit via the communication bus 16 On the basis of the information from 11, the PCS control unit 15 determines whether or not the idle stop is being performed (step S2).

If the determination result in step S2 is NO and it is determined that the engine is not idling stop, the operation start distance of the automatic brake read in step S1 is set (step S3), and the determination result in step S2 is YES. If it is determined that the engine is in idle stop, the automatic brake operation start distance is corrected and the corrected operation start distance is newly set in order to advance the operation start timing of the automatic brake (step S4). .

  After passing through the processing of step S3 and step S4 described above, the process proceeds to step S5, where the distance from the current obstacle by the laser radar 17 is compared with the set operation start distance of the automatic brake. It is determined whether or not the distance is smaller than the operation start distance (step S5).

  If the decision result in the step S5 is YES, based on a command from the PCS control unit 15, the ABS control unit 13 controls the brake hydraulic pressure control valve downstream of the master cylinder to operate the automatic brake (step S6). ), Then return to the start. On the other hand, if the determination result in step S5 is NO, it is not necessary to operate the automatic brake, and the process returns to the start.

  Therefore, according to the above-described embodiment, since the engine is automatically stopped when the automatic stop condition of the engine 3 is satisfied and the engine 3 is restarted when the restart condition of the engine is satisfied, the fuel consumption is reduced. Can be improved. In addition, the automatic brake operation control can prevent a driver from colliding with an obstacle even if the driver is late to notice an obstacle such as a forward vehicle in the traveling direction, thereby ensuring the safety of the driver. it can.

  Furthermore, since the stop distance to the front obstacle by the automatic brake when the engine 3 is automatically stopped by the idle stop control is controlled longer than when the engine 3 is not automatically stopped, the automatic brake Even if the restart condition of the engine 3 is satisfied based on an erroneous operation such as the driver accidentally removing his foot from the brake pedal after the stop by the vehicle, the vehicle arbitrarily advances forward in the traveling direction due to the creep force by the engine control unit 12 Even so, it is possible to give the driver enough time to notice the progress of the vehicle and perform the brake operation before the idle stop vehicle 1 collides with an obstacle ahead.

  Therefore, even if the vehicle is designed to improve fuel efficiency by automatically stopping the engine 3 during traveling and has a creep force generation function and an automatic brake function, the restart condition of the engine 3 is established after stopping by the automatic brake. It is possible to reliably avoid a collision with an obstacle due to the creep force caused by the operation.

  The present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the spirit of the present invention. For example, the present invention can also be applied to the case where the obstacle is behind the idle stop vehicle 1 and the shift lever of the idle stop vehicle 1 is in the “back” position and the vehicle moves backward by creep force.

  In the above-described embodiment, the operation start distance is as shown in FIG. 2 as the operation start timing of the automatic brake by the ABS control unit 13 when the engine 3 is not automatically stopped without executing the idle stop control. Although the case where the operation start time is Ta is illustrated in Sa, automatic braking is performed to stop at the minimum collision avoidance distance necessary for collision avoidance according to the relative speed between the traveling vehicle and the obstacle in the traveling direction. What is necessary is just to derive | lead-out the control start distance of the automatic brake optimal in order to operate | move suitably, and to control it. For example, as described above, for each relative speed between the host vehicle and the obstacle, the operation start distance of the automatic brake for the obstacle is obtained in advance, and this is mapped and stored in a predetermined memory or the like. In addition to reading the operation start distance according to the speed from the memory, the operation start distance may be obtained by calculation each time based on the current relative speed. In addition, the operation start distance of the automatic brake may be changed according to the inclination of the road, and in particular in the case of a downward inclination, it is controlled to make the operation start timing of the automatic brake by the switching means earlier. desirable.

  Furthermore, in the above-described embodiment, the drive source has been described as the engine 3, but the drive source may be a motor such as an electric vehicle, for example, and the present invention is also applied to a hybrid vehicle using both the engine and the motor. Can do.

  The creep force generating means is generated by the engine 3 or the torque converter 5 based on the control of the engine control unit 12 as described above, and is generated by sliding the clutch when the drive source is not the engine 3 but a motor. You may make it apply a technique.

  Furthermore, instead of the laser radar 17, a distance detecting means using one or two or more CCD cameras may be used.

DESCRIPTION OF SYMBOLS 1 Idle stop vehicle 3 Engine 11 Idle stop control part 12 Engine control part (creep force generation means)
15 PCS control unit (detection means, automatic brake means, switching means)

Claims (1)

In the vehicle control device that automatically stops the drive source that generates the driving force of the vehicle when a predetermined automatic stop condition is satisfied, and restarts the drive source when the predetermined restart condition is satisfied,
A creep force generating means for generating a creep force by driving the drive source;
Detection means for detecting the possibility of collision with an obstacle;
An automatic brake means for operating an automatic brake to stop the vehicle at a collision avoidance distance necessary to avoid a collision with the obstacle based on the possibility of collision detected by the detection means;
When the operation start timing when the automatic brake is operated during the automatic stop of the drive source during traveling is switched to an earlier timing than when the drive source is not automatically stopped, and the drive source is being automatically stopped the stopping distance by automatic brake, the vehicle control device, characterized in that it comprises a switching means you longer than the stopping distance by said automatic braking when not in automatic stop of the drive source.

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