JP2010137772A - Brake control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a brake control device capable of cooperatively performing brake control maintaining a stopping state after stop and brake control for releasing a stopping state after a stop. <P>SOLUTION: The brake control device 1 includes a first brake control unit 9 and a second brake control unit 10 in an ECU 2. When the vehicle speed of a vehicle M is a lower limit value or higher, the first brake control unit 9 predicts a collision of the vehicle M against an object, and if the collision is predicted, performs the brake control of the vehicle M and releases the brake control after the lapse of a predetermined time from the start of the brake control. When the vehicle speed of the vehicle M is an upper limit value or lower, the second brake control unit 10 predicts the collision of the vehicle M against the object, and when the collision is predicted, performs the brake control of the vehicle M so as to maintain the stop state of the vehicle M. Also, when brake control is performed by the first brake control unit 9, the second brake control unit 10 changes the vehicle speed upper limit value and a collision prediction threshold frequency. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a braking control device that performs braking control of a vehicle.

  As a conventional braking control device, for example, those described in Patent Documents 1 and 2 are known. When the obstacle ahead of the vehicle is detected under a predetermined condition, the braking control device described in Patent Document 1 stops the vehicle with a braking force for maintaining the stop state, and the vehicle is operated by a driver's operation. When the vehicle starts running again and the vehicle speed exceeds a predetermined value, the braking force is released.

Further, the braking control device described in Patent Document 2 detects the relative relationship between the host vehicle and the obstacle, and generates a braking force when it is determined that contact avoidance with the obstacle is impossible. After a predetermined duration has elapsed since the generation of the braking force, the generation of the braking force is stopped.
JP 2005-186936 A JP 2003-267200 A

  By the way, the desirable control that is performed after the vehicle is stopped (after braking) may differ depending on the situation when the braking control is performed. Therefore, for example, it is conceivable to switch the braking control by combining the braking control devices of Patent Document 1 and Patent Document 2 and setting the operating conditions for each. As an example, the brake control (Patent Document 2) for stopping the generation of the braking force when a predetermined duration has elapsed after the generation of the braking force (Patent Document 2) is based on the condition that the vehicle is traveling at a high speed, and the vehicle is stopped. The braking control to be held (Patent Document 1) includes setting the operating condition when the vehicle is traveling at a low speed. However, even in a situation where only the braking control in which the stop state is automatically released after the elapse of a predetermined duration due to the above operating conditions is performed, the brake control that maintains the stop state may be required. Accordingly, there is a need for a braking control device in which both braking control for maintaining the stopped state after stopping and braking control for releasing the stopped state after stopping are performed in cooperation.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a braking control device capable of cooperating braking control for maintaining a stopped state after stopping and braking control for releasing the stopped state after stopping.

  The present invention predicts a collision between a vehicle and an object when the operation state of the vehicle satisfies the first operating condition, and executes a braking control of the vehicle when a collision is predicted. When the first braking control means for releasing the braking control after a lapse of time and the second operating condition satisfying the second operating condition different from the first operating condition, the vehicle and the object are predicted to collide, and the collision is predicted. Then, the second braking control means for performing the braking control of the vehicle so as to hold the stop state of the vehicle, the second braking control means, when the braking control is performed by the first braking control means, It has a means to change the 2nd operation condition so that braking control by the 2nd braking control means becomes easy to be carried out.

  In the braking control apparatus according to the present invention, when the braking control is performed by the first braking control means, the second operating condition is changed so that the braking control is easily performed by the second braking control means. Thereby, even when the operation state of the vehicle does not satisfy the initially set second operating condition, the braking control is performed by the first braking control unit, so that the braking control is performed by the second braking control unit. May be implemented. In other words, the brake control is performed by the first brake control unit even in a situation where it is not normally determined whether or not the brake control for maintaining the vehicle stop state is performed by the second brake control unit. Then, by changing the second operating condition, it is determined whether or not the braking control by the second braking control means is necessary. If the braking control needs to be performed, the second braking control is performed. The braking control is performed by the means. Thus, both control such as braking control for maintaining the stopped state after the vehicle stops and braking control for releasing the stopped state after the vehicle stops can be performed in cooperation.

  Preferably, the first operating condition is a condition in which the traveling speed of the vehicle is equal to or higher than the first speed, and the second operating condition is a condition in which the traveling speed of the vehicle is equal to or lower than the second speed, and the second operating condition is The changing means is means for increasing the second speed when the braking control is performed by the first braking control means. In this case, the second operating condition used for the operation of the second braking control unit can be suitably changed, and the braking control by the second braking control unit is easily performed reliably.

  Preferably, the second braking control means includes means for lowering a collision prediction threshold for predicting a collision between the vehicle and the object when the braking control is performed by the first braking control means. In this case, when it is necessary to perform the braking control by the second braking control means, the braking control can be quickly performed.

  ADVANTAGE OF THE INVENTION According to this invention, the braking control which hold | maintains a stop state after a stop, and the brake control which cancels | releases a stop state after a stop can be implemented in cooperation. Thereby, effective braking control can be realized.

  DESCRIPTION OF EMBODIMENTS Hereinafter, a preferred embodiment of a braking control device according to the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a block diagram showing a schematic configuration of a braking control apparatus according to an embodiment of the present invention. In FIG. 1, a braking control device 1 is a device that cooperates to perform braking control that maintains a stopped state after stopping and braking control that releases the stopped state after stopping.

  The braking control device 1 includes an ECU (Electronic Control Unit) 2. The ECU 2 is connected to an obstacle monitoring sensor 3, an obstacle monitoring sensor 4, a vehicle speed sensor 5, a vehicle motion state monitoring sensor 6, a driver state monitoring sensor 7, and a brake actuator 8.

  The obstacle monitoring sensor 3 is a sensor for monitoring (detecting) an obstacle in front of the vehicle (for example, a vehicle, a roadside object, a pedestrian, a bicycle, etc.). The obstacle monitoring sensor 3 is, for example, a camera or a millimeter wave radar. The obstacle monitoring sensor 3 is provided at a predetermined location in front of the vehicle, and is arranged in a direction capable of detecting the front of the vehicle. The obstacle monitoring sensor 3 is used in a recognition (monitoring) system that assumes a high-speed traveling in a first braking control unit 9 described later. Therefore, as shown in FIG. 2A, for example, the detection area A1 in the obstacle monitoring sensor 3 is designed with priority on the obstacle detection distance, the detection distance is 100 m or more, and the detection visual field is the traveling direction of the vehicle M. The angle is about ± 10 to 15 °. The obstacle monitoring sensor 3 sends each obstacle information related to the detected obstacle to the ECU 2.

  The obstacle monitoring sensor 4 is a sensor for monitoring an obstacle ahead of the vehicle, like the obstacle monitoring sensor 3. The obstacle monitoring sensor 4 is used in a recognition system that assumes low-speed traveling in a second braking control unit 10 described later. Therefore, as shown in FIG. 2B, for example, the detection area A2 in the obstacle monitoring sensor 4 is designed with priority on the obstacle detection visual field, the detection distance is about 10 m, and the detection visual field is ± with respect to the traveling direction of the vehicle. It is 90 °. The obstacle monitoring sensor 4 sends each obstacle information related to the detected obstacle to the ECU 2.

  The vehicle speed sensor 5 detects the traveling speed (vehicle speed) of the host vehicle and sends a detection signal (vehicle speed signal) to the ECU 2.

  The vehicle motion state monitoring sensor 6 is a sensor that monitors (detects) the motion state of the vehicle. The vehicle motion state monitoring sensor 6 is, for example, an accelerator opening sensor or a steering sensor. The accelerator opening sensor detects the movement state of the vehicle M by measuring the opening of the accelerator throttle. The steering sensor detects the motion state of the vehicle M by detecting the steering angle of the steering wheel, for example, by determining whether or not the vehicle M is traveling on a curve. The vehicle movement state monitoring sensor 6 sends each vehicle information related to the detected movement state of the vehicle M to the ECU 2.

  The driver state monitoring sensor 7 is a sensor that monitors (detects) the state of the driver. The driver state monitoring sensor 7 is a face image capturing camera or the like, for example. The face image capturing camera detects the state of the driver by detecting the driver's face direction, for example, by determining whether or not the driver is driving aside. The driver state monitoring sensor 7 sends each driver information regarding the detected driver state to the ECU 2.

  The brake actuator 8 controls the braking of the brake by operating the actuator in accordance with the braking signal sent from the ECU 2.

  The ECU 2 includes a first braking control unit 9 and a second braking control unit 10. The ECU 2 further includes a memory (not shown).

  The first braking control unit 9 detects an obstacle based on each information and signal sent from the obstacle monitoring sensor 3, the vehicle speed sensor 5, the vehicle motion state monitoring sensor 6, and the driver state monitoring sensor 7, and A collision prediction between the vehicle M and the obstacle is performed. Specifically, the first braking control unit 9 performs a collision prediction between the vehicle M and the obstacle when the vehicle speed signal sent from the vehicle speed sensor 5 is equal to or higher than the vehicle speed lower limit value that is the first operating condition. Then, when a collision between the vehicle M and an obstacle is predicted, the first braking control unit 9 performs the braking control of the vehicle M, and releases the braking control after a predetermined time has elapsed from the start of the braking control. Then, a braking signal for instructing execution of braking movement control of the vehicle is sent to the brake actuator 8.

  The second braking control unit 10 detects the collision between the vehicle M and the obstacle based on the information and signals sent from the obstacle monitoring sensor 4, the vehicle speed sensor 5, the vehicle motion state monitoring sensor 6, and the driver state monitoring sensor 7. Make a prediction. Specifically, the first braking control unit 9 performs a collision prediction between the vehicle M and the obstacle when the vehicle speed signal sent from the vehicle speed sensor 5 is equal to or lower than the vehicle speed upper limit value that is the second operating condition. Then, when a collision between the vehicle M and an obstacle is predicted, the first braking control unit 9 sends a braking signal for instructing execution of the braking control of the vehicle M so as to maintain the stopped state of the vehicle M. To send.

  Further, the second braking control unit 10 sets the vehicle speed upper limit value and the number of collision prediction thresholds for predicting the collision between the vehicle M and the object when the first braking control unit 9 performs the braking control. 1 It changes according to the vehicle speed at the time of braking control being implemented by the braking control part 9.

  FIG. 3 is a flowchart showing details of a processing procedure of braking control executed by the first braking control unit 9.

In FIG. 3, first, a vehicle speed lower limit value V _h-min (for example, 15 km / h) stored in a memory (not shown) of the ECU 2 is read (step S01). Next, it is determined whether or not the current traveling speed of the vehicle M is equal to or higher than the vehicle speed lower limit value read from the memory (step S02). If it is determined that the traveling speed is equal to or greater than the traveling lower limit value, the process proceeds to step S03. On the other hand, when it is determined that the traveling speed is lower than the traveling lower limit value, the process ends.

  In step S03, an obstacle ahead of the vehicle M is detected. Specifically, an obstacle ahead of the vehicle M is detected based on image information and position information acquired by a camera or millimeter wave radar as the obstacle monitoring sensor 3. When an obstacle is detected in front of the vehicle M, a collision between the vehicle M and the obstacle is predicted (step S04). Specifically, when the same obstacle is detected for the collision prediction threshold number (n) or more, it is determined that there is an obstacle, and a collision between the vehicle M and the obstacle is predicted. At this time, the driver's state (for example, a side-view driving) determined based on each information sent from the vehicle movement state monitoring sensor 6 and the driver state monitoring sensor 7 and the movement state of the vehicle M (for example, during curve driving) are also included. It is taken into account as information for predicting a collision.

  Subsequently, when a collision between the vehicle M and an obstacle is predicted, it is determined whether or not the possibility of the collision is high (large) (step S05). If it is determined that the possibility of a collision is high, the process proceeds to step S06. On the other hand, if it is determined that the possibility of collision is not high, the process ends.

  In step S06, when the possibility of a collision between the vehicle M and an obstacle is high, a braking signal is sent to the brake actuator 8, and the braking control of the vehicle M is performed (brake ON). At this time, a collision possibility flag indicating that the braking control is performed by the first braking control unit 9 is set (step S07).

  Then, after execution of the braking control of the vehicle M, it is determined whether or not a predetermined time has elapsed (step S08). If it is determined that the predetermined time has elapsed, the process proceeds to step S09. On the other hand, if it is determined that the predetermined time has not elapsed, the same processing is repeated.

  In step S09, the braking control of the vehicle M is released (brake OFF). Then, as the brake is turned off, the collision possibility flag is canceled (step S10).

  FIG. 4 is a flowchart showing details of the processing procedure of the braking control executed by the second braking control unit 10. This process is executed in parallel with the process of the first braking control unit 9.

In FIG. 4, first, a vehicle speed upper limit value V _1-max (for example, 20 km / h) and a collision prediction threshold number (n) stored in a memory (not shown) of the ECU 2 are read (step S11). Next, it is determined whether or not a collision possibility flag is set in the first braking control unit 9 (step S12). If it is determined that the collision possibility flag is set, the process proceeds to step S13. On the other hand, if it is determined that the collision possibility flag is not set, the process proceeds to step S15.

In step S13, the vehicle speed upper limit V _1-max is changed so as to increase. Specifically, the vehicle speed upper limit value is changed so as to increase in proportion to the value of the vehicle speed V _h-cte when the braking control is performed by the first braking control unit 9. For example, when the vehicle speed when the braking control is performed by the first braking control unit 9 is 60 km / h, the vehicle speed upper limit value is set to 30 km / h, for example, and the first braking control unit 9 performs the braking control. When the vehicle speed is 80 km / h, the vehicle speed upper limit value is set to 40 km / h, for example.

If the collision possibility flag is set, the collision prediction threshold number n is changed (step S14). Specifically, n = n × (V so that the number of collision prediction thresholds decreases in proportion to the value of the vehicle speed (V _h−cte ) when the braking control is performed by the first braking control unit 9. _1−max / V _h−cte ). For example, when the vehicle speed when the braking control is performed by the first braking control unit 9 is 60 km / h, n = n × (20/60), and the number of collision prediction thresholds is reduced to 1/3. Is done.

In step S15, it is determined whether or not the current traveling speed of the vehicle M is equal to or lower than the vehicle speed upper limit value. At this time, when the collision possibility flag is not set, for example, V _l-max = 20 km / h set first is set as the vehicle speed upper limit value, and when the collision possibility flag is set, The changed value, for example, V _1−max = 30 km / h is set as the vehicle speed upper limit value. When it is determined that the current traveling speed of the vehicle M is equal to or less than the vehicle speed upper limit value, the process proceeds to step S16. On the other hand, when it is determined that the current traveling speed of the vehicle M is higher than the vehicle speed upper limit value, the process ends.

  In step S16, an obstacle ahead of the vehicle M is detected. When an obstacle is detected in front of the vehicle M, a collision between the vehicle M and the obstacle is predicted (step S17), and it is determined whether or not the possibility of the collision is high (large) (step S18). . If it is determined that the possibility of a collision is high, the process proceeds to step S19. On the other hand, if it is determined that the possibility of collision is not high, the process ends.

  In step S19, in response to the high possibility of a collision between the vehicle M and an obstacle, a braking signal is sent to the brake actuator 8 to perform braking control of the vehicle M (brake ON). Thereafter, whether or not the driver intends to release the brake is determined based on vehicle information (for example, an opening signal sent from an accelerator opening sensor or the like) (step S20). The intention to release the brake is, for example, an act of depressing the accelerator pedal after the vehicle M is stopped so as to start the driver. If it is determined that the driver intends to release the brake, the vehicle braking control is released (brake OFF) (step S21). On the other hand, when it is determined that the driver does not intend to release the brake, the same process is repeated.

As described above, in the braking control device 1 of the present embodiment, when the braking control is performed by the first braking control unit 9, the vehicle speed is set so that the braking control is easily performed by the second braking control unit 10. The upper limit value V _1-max and the collision prediction threshold number n are changed.

  Here, in a situation where the braking control is performed by the first braking control unit 9, that is, a situation where the vehicle M is traveling at a high speed, for example, a vehicle, a large roadside object, or the like can be considered as a main obstacle. On the other hand, in a situation where braking control is performed by the second braking control unit 10, that is, a situation where the vehicle M is traveling at a low speed, for example, pedestrians and bicycles (traffic weak people) can be considered as main obstacles. Therefore, when the obstacle is a vehicle or a large roadside object, etc., the braking control for releasing the stop state after the vehicle stops, and when the obstacle is a traffic weak person or the like, the stop state is maintained after the vehicle stops. Braking control is desirable. However, even when the vehicle is traveling at high speed, there is a possibility that the obstacle becomes a traffic weak person. Therefore, it is required to reliably operate the braking control for maintaining the stop state after the vehicle stops from the time of high speed traveling.

Therefore, in the present embodiment, in proportion to the vehicle speed V _h-cte when braking control of the first brake control unit 9 is performed as described above, initially set vehicle speed upper limit of the second brake control section 10 By changing the value V _{1 -max} to be larger, the second braking control unit 10 can easily perform the braking control even when the traveling speed of the vehicle M is equal to or higher than the vehicle speed upper limit value. That is, the determination result of the collision prediction of the first braking control unit 9 is reflected in the recognition / determination of the second braking control unit 10. As a result, even when the traveling speed is such that the second braking control unit 10 does not normally determine whether or not the braking control for maintaining the vehicle stop state is performed, the first braking control unit 9 performs braking. When the control is performed, it is determined whether or not the second braking control unit 10 needs to perform the braking control by changing the vehicle speed upper limit value V _1-max , and the braking control needs to be performed. In this case, the second braking control unit 9 performs the braking control for holding the stopped state after the stop. Thus, both control such as braking control for maintaining the stopped state after the vehicle M stops and braking control for releasing the stopped state after the vehicle M stops can be performed in cooperation. As a result, effective braking control can be realized.

  Further, when the braking control is performed by the first braking control unit 9, the first braking control unit 9 sets the collision prediction threshold number n for predicting the collision between the vehicle M and the object in the second braking control unit 10. Is reduced in proportion to the speed when the braking control is performed. As a result, when the braking control by the second braking control unit 9 needs to be performed, it is possible to shorten the collision prediction determination time, to quickly perform the braking control, and to increase the responsiveness.

The present invention is not limited to the above embodiment. For example, in the above embodiment, the vehicle speed upper limit value of the second braking control unit 10 is changed in proportion to the vehicle speed V _h-cte when the braking control is performed by the first braking control unit 9. For example, the upper limit value may be changed to be the same as the vehicle speed when the braking control is performed by the first braking control unit 9.

  In the above embodiment, the second braking control unit 9 indicates that the braking control is performed by the first braking control unit 9 based on the collision possibility flag set when the braking control by the first braking control unit 9 is performed. 10 is recognized, but may be recognized by other methods. For example, when a sensor (yaw sensor) for detecting the vertical angle of the vehicle M is mounted on the vehicle M and the braking control is performed by the first braking control unit 9, the angle when the vehicle sinks forward, that is, the dive angle It is good also as a structure which recognizes this and correct | amends and recognizes the center of an up-and-down sensor axis upward supposing that the up-and-down axis of a sensor has faced the predetermined amount.

1 is a block diagram illustrating a schematic configuration of a braking control device according to an embodiment of the present invention. It is a figure which shows the detection distance and detection visual field of an obstruction monitoring sensor. It is a flowchart which shows the detail of the process sequence of the brake control performed by the 1st brake control part. It is a flowchart which shows the detail of the process sequence of the brake control performed by the 2nd brake control part.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Braking control apparatus, 2 ... ECU (1st braking control means, 2nd braking control means), 9 ... 1st braking control part (1st braking control means), 10 ... 2nd braking control part (2nd braking control) Means), M ... vehicle.

Claims (3)

When the operation state of the vehicle satisfies the first operating condition, a collision prediction between the vehicle and the object is performed, and when the collision is predicted, the vehicle is subjected to the braking control, and the predetermined braking from the start of the braking control is performed. First braking control means for releasing the braking control after a lapse of time;
When the operation state of the vehicle satisfies a second operation condition different from the first operation condition, a collision prediction between the vehicle and the object is performed, and when the collision is predicted, the stop state of the vehicle is maintained. Second braking control means for performing braking control of the vehicle as described above,
The second braking control unit changes the second operating condition so that the braking control by the second braking control unit is easily performed when the braking control is performed by the first braking control unit. A braking control device comprising means. The first operating condition is a condition that the traveling speed of the vehicle is equal to or higher than the first speed,
The second operating condition is a condition in which the traveling speed of the vehicle is equal to or lower than a second speed,
2. The brake control according to claim 1, wherein the means for changing the second operating condition is means for increasing the second speed when the brake control is performed by the first brake control means. 3. apparatus. The second braking control means has means for lowering a collision prediction threshold for predicting a collision between the vehicle and the object when the braking control is performed by the first braking control means. The braking control device according to claim 1 or 2.

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