JP5496176B2 - Collision damage reduction system - Google Patents

Description

  The present invention relates to a collision damage reduction system mounted on a vehicle provided with an idle stop control means.

  In recent years, in order to avoid a collision with the preceding vehicle due to driver's carelessness, etc., to establish a predetermined collision avoidance condition, to control the automatic brake or reduce the damage to the passenger due to the collision with the rear vehicle, A collision damage reduction system that performs movement control so that the headrest approaches the occupant's head when the possibility of a collision with a rear vehicle is high has been proposed.

  In order to improve the fuel efficiency of a vehicle, an idle stop system that performs engine stop control when a predetermined engine automatic stop condition is satisfied has also been proposed. This system stops the engine when the vehicle is at zero speed, the brake is depressed, or the transmission gear position is neutral, and the driver removes the foot from the brake pedal or steps on the accelerator pedal. The engine is restarted when it is changed. Thus, fuel consumption can be improved as much as there is no idling state while the vehicle is stopped.

  In recent years, vehicles equipped with these systems have been considered, and problems associated therewith have occurred. For example, when a collision damage reduction system that controls movement of the headrest and an idle stop system are installed, the collision damage reduction system while the engine is stopped operates using the power of the battery installed in the vehicle. When the charge amount of the battery is small or the battery is deteriorated, the movement control of the headrest may not operate.

  Therefore, conventionally, when the possibility of a collision with a vehicle behind is high while the engine is stopped, there is a technology that stabilizes the power system by restarting the engine in advance and operates the headrest movement control function normally. It has been proposed (see Patent Document 1).

JP 2010-254239 (see paragraphs 0028-0032, FIG. 1, etc.)

  By the way, in order to further reduce fuel consumption of a vehicle, a vehicle has been developed in which automatic engine stop control in an idle stop system is performed without waiting for the vehicle to stop (for example, 7 km / h or less). Although the operating speed range of the damage mitigation system is 15 km / h or higher, vehicles that are expanded to an extremely low speed range are being developed. Therefore, in a vehicle in which both systems are installed, the operating speed regions of both systems may overlap. In such a case, the following problems occur.

  In a vehicle equipped with a collision damage reduction system that performs automatic brake control and an idle stop system due to the establishment of a predetermined collision avoidance condition, if the operating speed areas of both systems overlap, for example, during the operation of the collision damage reduction system When the engine is automatically stopped by the idle stop system, the vehicle is controlled to stop at a desired stop position by changing the deceleration of the vehicle due to engine braking or by changing the braking distance due to fluctuations in engine negative pressure. Becomes difficult. If the engine is restarted while the collision damage mitigation system is in operation, the collision damage mitigation system may stop operating due to a voltage drop during cranking, and collision with an obstacle may be unavoidable.

  However, the invention of Patent Document 1 aims to stabilize the power supply system by restarting the engine while the vehicle is stopped and to normally operate the collision damage mitigation system. Can not respond.

  The present invention has been made in view of the above problems, and the collision damage mitigation system operates normally by preventing the engine from being automatically stopped or restarted by the idle stop system during the operation of the collision damage mitigation system. It is an object of the present invention to provide a collision damage mitigation system that can reliably reduce the collision damage of passengers.

In order to achieve the above object, in the collision damage alleviating system of the present invention, a vehicle provided with an idle stop control means for performing engine stop control when a predetermined engine automatic stop condition is established at the deceleration stage of the host vehicle. In a collision damage mitigation system that is mounted on a vehicle and that controls automatic braking when a predetermined collision avoidance condition is satisfied and that avoids collision with an obstacle in the traveling direction of the own vehicle, the collision between the own vehicle and the obstacle And determining means for determining the possibility, and when the determining means determines that there is a high possibility of collision between the host vehicle and the obstacle before starting the control of the automatic brake, the control of the automatic brake is started. the is characterized in that it comprises an idle stop prohibition means for prohibiting the stop control of the engine by the idle stop control means (claim before ).

  Further, after the completion of the brake control, the prohibition of the engine stop control by the idle stop prohibiting means may be canceled (Claim 2).

According to the first aspect of the present invention, if the determination means determines that there is a high possibility of a collision before the start of the automatic brake control of the collision damage reducing system , the idle stop prohibiting means is set before starting the automatic brake control. Since the automatic stop of the engine by the idle stop control means is prohibited, the collision damage reduction system can be operated normally without the engine being automatically stopped or restarted during the operation of the collision damage reduction system. Therefore, it becomes difficult to stop the vehicle to the desired position by stopping the engine while the collision damage mitigation system is operating, or the collision damage mitigation system is activated by restarting the engine while the system is operating. There is no risk of stopping and avoiding collisions with obstacles.

  According to the second aspect of the present invention, after the brake control is completed (after the collision damage reduction system is activated), the prohibition of the engine stop control by the idle stop prohibiting means is canceled. Automatically stops and the idling state disappears. As a result, the fuel consumption of the vehicle can be reduced.

It is a block diagram of the collision damage reduction system concerning one Embodiment of this invention. It is operation | movement explanatory drawing of the collision damage reduction system of FIG. It is operation | movement explanatory drawing of the collision damage reduction system of FIG. It is a flowchart for operation | movement description of the collision damage reduction system of FIG.

  A collision damage reducing system according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a block diagram of a collision damage mitigation system according to an embodiment of the present invention, FIG. 2 is an explanatory diagram for determining the possibility of collision, and FIG. 3 estimates the presence or absence of a driver's intention to drive. It is explanatory drawing of an operation intention estimation means.

  As shown in FIG. 1, the collision damage mitigation system of the present embodiment is a system mounted on an idle stop vehicle 1 (hereinafter also referred to as a vehicle 1) provided with an idle stop control means, and has a predetermined collision avoidance condition. When it is established, the automatic brake is controlled to avoid a collision between the obstacle in the traveling direction of the vehicle 1 and the vehicle 1, but it is determined by the determination means 5 described later that the possibility of a collision between the vehicle 1 and the obstacle is high. In this case, the engine is prevented from being stopped and restarted during the brake control by prohibiting the automatic engine stop control by the idle stop control means before the start of the automatic brake control. This will be described in detail below.

(Collision damage reduction system)
The laser sensor 2 shown in FIG. 1 includes a laser radar, and as is well known, detects the distance between an obstacle in the traveling direction of the vehicle 1 and the vehicle 1 from the time difference between transmission and reception of laser pulses, Detect the relative speed with the object. These detections may be performed using, for example, an ultrasonic sensor or a CCD camera.

The collision avoidance brake control means 3 shown in FIG. 1 comprises a microcomputer, and when the relationship between the distance and relative speed between the vehicle 1 and the obstacle detected by the laser sensor 2 is a predetermined collision avoidance condition, An automatic brake request signal is transmitted to the brake ECU 4, and the brake ECU 4 receiving the automatic brake request signal controls the brake so that the vehicle 1 stops at a desired position at a predetermined deceleration (for example, -6 m / s ² ).

  The predetermined collision avoidance condition will be described with reference to FIG. In FIG. 2, the vertical axis indicates the collision margin time and the horizontal axis indicates the time, and so-called TTC (Time To Collation), which is an index used to determine the operation timing of the collision avoidance system conventionally. ing.

  In this embodiment, a predetermined collision avoidance condition is determined using this TTC value as an index. The TTC value is calculated by dividing the distance between the vehicle 1 and the obstacle detected by the laser sensor 2 by the relative speed (TTC (second) = distance between the vehicle 1 and the obstacle ÷ relative speed). The TTC value indicates that the lower the value, the higher the possibility of collision with an obstacle.

  Normally, the TTC value is about 2 seconds when the driver is driving with an appropriate inter-vehicle distance from the preceding vehicle. In this embodiment, as shown in FIG. 2, the TTC value is 1 second or less. This is determined as a collision avoidance condition. Therefore, the collision avoidance brake control means 3 calculates a TTC value from the distance and relative speed between the vehicle 1 and the obstacle detected by the laser sensor 2, and when the value becomes 1 second or less, which is a collision avoidance condition. At (time B), an automatic brake request signal is transmitted to the brake ECU 4, and the brake ECU 4 receiving the signal controls the brake, whereby the vehicle 1 stops at a desired position at a predetermined deceleration rate. Avoid collisions with obstacles. In addition, you may make it the collision avoidance brake control means 3 acquire the information regarding a TTC value from the determination means 5 mentioned later.

(Idle stop control means: Idle stop system)
The idle stop control means is a system that performs engine stop control when a predetermined engine automatic stop condition is satisfied, thereby reducing fuel consumption of the vehicle 1.

  The idle stop control means 6 shown in FIG. 1 comprises a microcomputer, and automatically stops the engine via the engine ECU 7 when a predetermined engine automatic stop condition is satisfied, or when a predetermined engine restart condition is satisfied. The engine is automatically restarted via the starter 8.

  Further, the idle stop control means 6 detects a vehicle speed sensor 10 for detecting the vehicle speed of the vehicle 1 installed in the vehicle 1 and a brake stepping amount via a bus 15 for in-vehicle communication such as CAN (Controller Area Network). It is connected to various sensors such as the brake sensor 12 to acquire the information sequentially. The idle stop control means 6 performs automatic engine stop and restart control based on the information.

  The predetermined engine automatic stop condition is usually when the vehicle 1 is at a speed of 0 and the brake is stepped on or the gear position of the transmission is in a neutral position. In this embodiment, in addition to these, The engine automatic stop condition is that the vehicle speed of the vehicle 1 is, for example, 7 km / h or less when the brake is depressed. However, even if these conditions are satisfied, if the determination means 5 described later determines that the vehicle 1 is highly likely to collide with an obstacle, the idle stop prohibiting means 13 controls the automatic engine stop. Is prohibited.

  The predetermined engine restart condition is when the driver removes his or her foot from the brake pedal, depresses the accelerator pedal, or the gear position of the transmission becomes other than neutral. 6 automatically restarts the engine via the starter 8.

  The determination means 5 is composed of a microcomputer, and determines the possibility of collision with an obstacle based on the distance and relative speed between the vehicle 1 and the obstacle detected by the laser sensor 2. In this embodiment, the possibility of collision with an obstacle is determined using the TTC value used when determining a predetermined collision avoidance condition described with reference to FIG. 2 as an index. For example, as shown in FIG. 2, the threshold value is set to 1.2 seconds where the TTC value is slightly larger than the collision avoidance condition (1.0 second). The determination means 5 calculates a TTC value from the distance and relative speed between the vehicle 1 and the obstacle detected by the laser sensor 2, and when the value is 1.2 seconds or less (time A), the obstacle It is determined that there is a high possibility of a collision with Note that this threshold value (1.2 seconds) only needs to be equal to or greater than the collision avoidance condition (1.0 seconds), and may be appropriately changed, for example, the threshold value is set to 1.4 seconds.

  The operation intention estimation means 14 is composed of a microcomputer, and estimates whether or not the driver has a driving intention based on the accelerator opening indicating the operation amount of the accelerator pedal, the steering operation amount, and the brake depression amount. For example, as shown in FIG. 3, when the magnitude of the steering operation amount of the driver is equal to or greater than a predetermined amount within a predetermined time, it is estimated that the driver intends to drive during that time, and the amount is equal to or less than the predetermined amount Estimates that the driver does not intend to drive. The same applies to the amount of change in the accelerator opening and the amount of change in the brake depression amount. If any one of the magnitude of the steering operation amount, the change amount of the accelerator opening, and the change amount of the brake depression amount is a predetermined amount or more, the operation intention estimation means 14 estimates that the driver has a driving intention. .

  The accelerator sensor 9 for detecting the accelerator opening, the steering angle sensor 11 for detecting the steering angle of the steering, and the brake sensor 12 for detecting the brake depression amount are connected to the operation intention estimating means 14 via the bus 15 in CAN communication. Therefore, the operation intention estimation means 14 sequentially acquires information detected by the sensors 9, 11, and 12.

  The idle stop prohibiting means 13 comprises a microcomputer, and is based on the presence or absence of the driver's driving intention estimated by the operation intention estimating means 14 and the possibility of collision with an obstacle determined by the determining means 5. The prohibition / permission control of the automatic engine stop control by the control means 6 is performed. In this case, when the determination unit 5 determines that the possibility of collision with the obstacle is high (the TTC value is 1.2 seconds or less), the idle stop prohibiting unit 13 is performing brake control by the collision avoidance brake control unit 3. Since there is a possibility that the engine is automatically stopped or restarted, the engine automatic stop control by the idle stop control means 6 is prohibited.

  Even if the determination means 5 determines that the possibility of collision with an obstacle is high, if the operation intention estimation means 14 estimates that the driver has a driving intention, the collision avoidance brake control means Even if the engine is automatically stopped or restarted during the brake control by 3, it is considered that the collision with the obstacle can be avoided by the driving operation of the driver. Regardless of the determination result by the determination means 5, the automatic stop control of the engine by the idle stop control means 6 is permitted.

  Then, after the determination means 5 determines that the possibility of collision with an obstacle is high, the idle stop prohibiting means 13 prohibits the automatic stop control of the engine by the idle stop control means 6, and then the collision avoidance brake control means 3 If the vehicle 1 stops due to execution of automatic brake control, the idle stop prohibiting means 13 performs automatic engine stop control by the idle stop control means 6 after the stop (for example, 1.5 seconds after stopping). The idle stop control means 6 performs engine stop control when the predetermined engine automatic stop condition is satisfied.

  Next, the idle stop control process in this embodiment will be described with reference to the flowchart of FIG.

  First, the idle stop prohibiting means 13 determines whether or not the automatic brake control is being executed in the collision avoidance brake control means 3 (step S1). The engine automatic stop control by the idle stop control means 6 is prohibited (step S4).

  If the automatic brake control is not executed in the collision avoidance brake control means 3, step S1 is passed through NO, and in step S2, the operation intention estimation means 14 determines the driver's operation amount (accelerator opening degree). , Whether or not the driver intends to drive is estimated based on the amount of depression of the brake pedal and the amount of steering operation.

  If the operation intention estimation means 14 estimates that the driver has no intention to drive because the accelerator opening, the brake pedal operation amount, and the steering operation amount are all equal to or less than the predetermined amount, step S2 is passed in NO. Then, the determination unit 5 determines whether or not the TTC value calculated based on the distance between the vehicle 1 and the obstacle and the relative speed is equal to or less than a threshold value (1.2 seconds) (step S3). If the operation intention estimation unit 14 estimates that the driver has a driving intention because any one of the operation amounts is equal to or greater than the predetermined amount, step S2 is passed through YES, and the idle stop prohibiting unit 13 Automatic stop control of the engine by the stop control means 6 is permitted (step S5), and the idle stop control means 6 executes engine stop control when the predetermined engine automatic stop condition is satisfied, and idle stop control processing is performed. Exit.

  In step S3, when the TTC value is 1.2 seconds or less, the determination unit 5 prohibits the automatic stop control of the engine by the idle stop control unit 6 because the possibility of collision between the vehicle 1 and the obstacle is high. (Step S4), and the idle stop control process is terminated. If the TTC value is 1.2 seconds or more, the determination means 5 permits the engine automatic stop control by the idle stop control means 6 assuming that the possibility of collision between the vehicle 1 and the obstacle is low (step S5). The idle stop control means 6 executes engine stop control when the predetermined engine automatic stop condition described above is satisfied, and ends the idle stop control process.

  Therefore, according to the above-described embodiment, if the determination unit 5 determines that there is a high possibility of a collision before the automatic braking control of the collision avoidance brake control unit 3 is started, the idle stop prohibiting unit 13 is set to the idle stop control unit 6. In order to prohibit the automatic stop of the engine, the collision damage mitigation system can be operated normally without the engine being automatically stopped or restarted during the operation of the automatic brake control by the collision avoidance brake control means 3. . Therefore, it becomes difficult to stop and control the vehicle 1 to a desired position by stopping the engine during automatic brake control, or the collision damage reduction system is stopped by restarting the engine during brake control. There is no risk of avoiding collisions with obstacles.

  Even if it is determined by the determination means 5 that the possibility of collision between the vehicle 1 and the obstacle is high, if it is estimated by the operation intention estimation means 14 that the driver has a driving intention, the idle stop prohibiting means 13 permits automatic engine stop by the idle stop control means 6, and prohibition of the idle stop control is ensured when, for example, the driver is asleep while driving and there is a high possibility of collision with an obstacle. Only when the brake control by the collision avoidance brake control means 3 is necessary. Therefore, the idle stop system is not stopped more than necessary, and the fuel consumption of the vehicle 1 can be reduced while reliably avoiding the collision between the vehicle 1 and the obstacle.

  Even if the engine automatic stop control of the idle stop control means 6 is prohibited, after the automatic brake control by the collision avoidance brake control means 3 is executed (for example, 1.5 seconds after the vehicle 1 stops) Since the prohibition is canceled (permission of engine stop control by the idle stop control means 6), the idle stop system is not unnecessarily stopped.

  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, in the above-described embodiment, a configuration in which the operation intention estimation unit 14 is not provided may be used. In this case, if the determination means 5 determines that the possibility of collision between the vehicle 1 and the obstacle is high regardless of whether the driver intends to drive or not, the idle stop prohibiting means 13 causes the idle stop control means 6 to The engine automatic stop control may be prohibited. By doing in this way, when the possibility of collision with an obstacle is high, automatic brake control by the collision avoidance brake control means 3 is reliably executed, and collision with the obstacle can be avoided.

  Further, in the above-described embodiment, the predetermined collision avoidance condition is that the TTC value is 1 second or less, but this value may be appropriately changed, for example, 0.8 seconds or less.

DESCRIPTION OF SYMBOLS 2 ... Laser sensor 3 ... Collision avoidance brake control means 5 ... Judgment means 6 ... Idle stop control means 13 ... Idle stop prohibition means

Claims (2)

When a predetermined engine automatic stop condition is established at the deceleration stage of the host vehicle, it is mounted on a vehicle equipped with an idle stop control means for performing engine stop control, and the automatic brake is controlled by satisfying a predetermined collision avoidance condition. In the collision damage reduction system for avoiding a collision with an obstacle in the traveling direction of the own vehicle,
Determination means for determining the possibility of collision between the host vehicle and the obstacle;
When the determination means determines that the possibility of collision between the host vehicle and the obstacle before the start of the automatic brake control is high, the idle stop control means before the automatic brake control is started. A collision damage mitigation system comprising: an idle stop prohibiting unit that prohibits engine stop control. 2. The collision damage alleviating system according to claim 1, wherein after the completion of the brake control, the prohibition of the engine stop control by the idle stop prohibiting unit is canceled.

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