JP2017043303A - Braking force control device and braking force control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a braking force control device that can reduce an alarm and braking that a driver feels troublesome or that may cause a traffic flow disturbance, and to provide a braking force control method.SOLUTION: The braking force control device 160 includes: an alarm/braking control part 164, 168 for controlling alarm and braking based on distance information and relative speed information between own vehicle and a forward vehicle; and an alarm/braking suppression part 300 for suppressing the control when an accelerator pedal depression increase amount within a predetermined period is equal to or higher than a second threshold after an accelerator pedal depression amount is equal to or lower than a first threshold.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a braking force control device and a braking force control method.

  In recent years, in the automobile industry, in order to ensure the safety of passengers, development of a driving support device that supports driving of a driver is in progress. As this type of device, there has been proposed a driving support device that avoids collision between the own vehicle and an obstacle (for example, a preceding vehicle that travels in front of the traveling direction of the own vehicle) and reduces damage at the time of collision by automatic brake control. (For example, refer to Patent Document 1). Such a driving assistance apparatus is called AEBS (Advanced Emergency Braking System).

  In the driving assistance device, when the collision prediction time between the own vehicle and the obstacle is calculated using a radar sensor provided in the vehicle, and the collision prediction time becomes shorter than a predetermined time, In order to notify the effect, driving support control such as an alarm and an automatic brake (alarm brake) is executed. This predetermined time is a limit time during which a collision can be avoided by the driver's normal braking operation or steering. Also, when the driver does not perform a collision avoidance operation even though the driving support control is executed, or when an obstacle immediately before the vehicle is suddenly detected, the collision prediction time is set to a time shorter than the predetermined time described above. When the set time is shorter than the set time, automatic brake (emergency brake) control stronger than the alarm brake, which is automatic brake control for avoiding a collision, is executed. This set time is a limit time that can avoid a collision with an obstacle by emergency braking.

JP 2009-18721 A

  By the way, the above-mentioned driving support device is very effective in avoiding collision and reducing damage at the time of collision, but depending on the situation, warning and braking by the driving support device may cause trouble for the driver. Or disturb the traffic flow.

  An object of the present invention is to provide a braking force control device and a braking force control method capable of reducing alarms and braking that cause a driver to feel troublesome or disturb traffic flow.

One aspect of the braking force control device of the present invention is:
An alarm / brake control unit that executes alarm and / or braking control based on distance information and relative speed information between the host vehicle and the preceding vehicle;
An alarm / braking suppression unit that suppresses the control when the amount of depression of the accelerator pedal within a predetermined period becomes equal to or greater than a second threshold after the amount of depression of the accelerator pedal becomes equal to or less than a first threshold; ,
It comprises.

One aspect of the braking force control method of the present invention is:
An alarm / brake control step for executing alarm and / or braking control based on distance information and relative speed information between the host vehicle and the preceding vehicle;
An alarm / braking suppression step for suppressing the control when the depression amount of the accelerator pedal within a predetermined period becomes equal to or greater than a second threshold after the depression amount of the accelerator pedal becomes equal to or less than a first threshold; ,
including.

  According to the present invention, it is possible to realize a braking force control device and a braking force control method that can reduce alarms and braking that cause a driver to feel troublesome or disturb traffic flow.

It is a figure which shows the structure of the vehicle and braking force control apparatus in this Embodiment. It is a flowchart with which it uses for description of the warning and the suppression process of braking in the braking force control apparatus in this Embodiment. It is a timing chart with which it uses for description of the alarm and braking suppression process in the braking force control apparatus in this Embodiment. It is a figure which shows the example which changes the threshold value for suppression according to the position of an accelerator pedal.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a functional block diagram showing a configuration of vehicle 100 in the present embodiment. In the present embodiment, vehicle 100 is, for example, a large vehicle such as a truck equipped with an inline 6-cylinder diesel engine. Although not shown in detail because it is a well-known configuration, the vehicle 100 includes a drive system that drives the vehicle 100 as an engine, a clutch, a transmission (transmission), a propeller shaft (propeller shaft), a differential device (differential gear), a drive. It has a shaft (drive shaft) and wheels. The power of the engine is transmitted to the transmission via the clutch, and the power transmitted to the transmission is transmitted to the wheels via the propulsion shaft, the differential and the drive shaft. As a result, the power of the engine is transmitted to the wheels and the vehicle 100 travels.

  As shown in FIG. 1, the vehicle 100 includes a forward vehicle detection unit 120, a speed detection unit 140, a braking force control device 160, an alarm unit 180, and a braking unit 200.

  The forward vehicle detection unit 120 detects a forward vehicle traveling in front of the traveling direction of the host vehicle 100 using electromagnetic waves such as millimeter waves and laser light. Specifically, the forward vehicle detection unit 120 transmits electromagnetic waves in front of the vehicle 100 while scanning in the left-right direction, and receives reflected waves that have been reflected. And front vehicle detection part 120 judges that a front vehicle does not exist when a reflected wave cannot be received. On the other hand, the forward vehicle detection unit 120 determines that there is a forward vehicle when the reflected wave can be received, and information about each reflection point (each detection point) that can receive the reflected wave (scanning direction in the left-right direction) Corner, transmission time, reception time, reflection intensity, and the like) and the distance and relative speed between the host vehicle 100 and the preceding vehicle are calculated. The forward vehicle detection unit 120 outputs various information (distance information, relative speed information) calculated when there is a forward vehicle and when there is a forward vehicle to the braking force control device 160 as detection signals. In addition, as a means to detect a front vehicle, the other means using the camera apparatus, the inter-vehicle communication apparatus, etc. which image the object ahead of the vehicle 100 may be used.

  The speed detection unit 140 is a vehicle speed sensor mounted on the vehicle 100, for example, and detects the actual speed (traveling speed) of the vehicle 100. Then, the speed detection unit 140 outputs the detected actual speed to the braking force control device 160. Note that the speed detection unit 140 may detect the actual speed of the vehicle 100 from the rotational speed of an engine mounted on the vehicle 100 or the like.

  The braking force control device 160 automatically controls the braking amount of the vehicle 100 separately from a braking instruction by a brake pedal (not shown). In the braking force control device 160, alarm control, alarm brake control, and emergency brake control are set as three types of braking control with different braking levels.

  The alarm control is the control with the lowest braking level that is executed first when the braking force control device 160 determines that there is a possibility of a collision with the preceding vehicle. The alarm control urges the driver to perform a collision avoidance operation such as a brake operation (braking operation) by alerting the driver to the vehicle ahead by outputting an alarm sound or displaying a meter.

  The alarm brake control is a control executed when an appropriate collision avoidance operation (such as steering or brake operation by the driver) of the driver is not performed for the alarm control. In the alarm brake control, light automatic brake (braking) intervention is performed, and the driver is alerted again by the automatic brake.

  The emergency brake control is the control with the highest braking level that is executed when the driver's appropriate collision avoidance operation is not performed even for the alarm brake control. In the emergency brake control, strong automatic brake (braking) intervention is performed, and the collision between the host vehicle 100 and the preceding vehicle is avoided by the automatic brake.

  As shown in FIG. 1, the braking force control device 160 includes a collision margin time calculation unit 162, an alarm control unit 164, a target deceleration calculation unit 166, and a braking control unit 168.

  The collision allowance time calculation unit 162 is highly likely to collide with the host vehicle 100 and the preceding vehicle based on the distance and relative speed between the host vehicle 100 and the preceding vehicle output from the preceding vehicle detection unit 120. It is determined whether or not it is in a state. Specifically, the collision margin time calculation unit 162 calculates a collision margin time (TTC: Time To Collation) by dividing the distance between the host vehicle 100 and the preceding vehicle by the relative speed.

  The collision margin time calculation unit 162 may collide with the host vehicle 100 and the preceding vehicle when the calculated collision margin time value is, for example, 3.0 [seconds] or less and 1.8 [seconds] or more. Is determined to be in the first state before the occurrence of a collision (in other words, the state in which the alarm control needs to be executed), and the fact is notified to the alarm control unit 164. Further, the collision margin time calculation unit 162 may cause the host vehicle 100 and the preceding vehicle to collide when the value of the collision margin time is, for example, less than 1.8 [seconds] and not less than 0.6 [seconds]. Is a second pre-collision state (in other words, a state where the execution of the alarm brake control is necessary), which is higher than the first pre-collision state, and that fact is calculated by the alarm control unit 164 and the target deceleration calculation. Notification to the unit 166. Further, when the value of the collision margin time is less than 0.6 [seconds], for example, the collision margin time calculation unit 162 is more likely to collide with the host vehicle 100 and the preceding vehicle than in the second pre-collision state. It is determined that the state is a high third pre-collision state (in other words, a state in which emergency brake control needs to be executed), and the fact is notified to the alarm control unit 164 and the target deceleration calculation unit 166.

  When the alarm control unit 164 receives a notification from the collision margin time calculation unit 162 that it has been determined that the first pre-collision state has occurred, the alarm control unit 164 outputs an alarm control signal to the alarm unit 180 and An alarm (for example, a meter display or a speaker sound) is generated to notify the driver that there is a possibility that the vehicle will collide with the vehicle before the first collision occurs. Further, when the alarm control unit 164 receives a notification from the collision margin time calculation unit 162 that it is determined that the state is the second pre-collision state, the alarm control unit 164 outputs a control signal to the alarm unit 180 and An alarm for notifying the driver that the possibility of collision with the vehicle is the second pre-collision state is generated. When the alarm control unit 164 receives a notification from the collision margin time calculation unit 162 that it is determined that the state is the third pre-collision state, the alarm control unit 164 outputs a control signal to the alarm unit 180 to An alarm is generated to notify the driver that the possibility of collision with the vehicle is the third pre-collision state. Note that the driver may be informed that there is a high possibility that the host vehicle 100 and the preceding vehicle will collide by causing a light emitting device such as a lamp to emit light instead of the meter display or speaker sound.

  When the target deceleration calculation unit 166 receives a notification from the collision margin time calculation unit 162 that it has been determined that the state is the second pre-collision state, the target deceleration calculation unit 166 is necessary to alert the driver of the collision avoidance operation. The target deceleration (hereinafter, “first target deceleration”) is output to the braking control unit 168. Further, when the target deceleration calculation unit 166 receives a notification from the collision allowance time calculation unit 162 that it is determined that the state is the third pre-collision state, the target deceleration 100 requires a target necessary for collision avoidance between the host vehicle 100 and the preceding vehicle. The deceleration (hereinafter, “second target deceleration”) is output to the braking control unit 168.

  The brake control unit 168 is a brake control device such as an EBS (Electronic Braking System). When the first target deceleration is output from the target deceleration calculation unit 166, the braking control unit 168 differentiates the actual speed output from the speed detection unit 140 with respect to the actual vehicle 100 obtained by differentiating for a predetermined time. The braking unit 200 is controlled so that the deceleration becomes the first target deceleration, and a first braking force (alarm brake) such as an engine brake is generated for the host vehicle 100. In addition, when the second target deceleration is output from the target deceleration calculation unit 166, the braking control unit 168 controls the braking unit 200 so that the actual deceleration of the host vehicle 100 becomes the second target deceleration. A second braking force (emergency brake) larger than the first braking force is generated on the host vehicle 100.

  The braking unit 200 is, for example, a foot brake that applies resistance to the wheels of the vehicle 100, and applies braking force to the vehicle 100 under the control of the braking control unit 168. The braking unit 200 is not limited to a foot brake as long as it generates a braking force for the vehicle 100. For example, the braking unit 200 may be an auxiliary brake such as a retarder that provides resistance to the propulsion shaft (propeller shaft) or an exhaust brake that applies load to the engine.

  In addition to this configuration, in the case of the present embodiment, the braking force control device 160 includes an alarm / braking suppression unit 300. The alarm / braking suppression unit 300 receives a signal indicating the depression amount of the accelerator pedal, and suppresses the control by the alarm control unit 164 and the braking control unit 168 when the depression amount of the accelerator pedal satisfies a predetermined condition. In the case of the present embodiment, the warning / braking suppression unit 300 increases the amount of depression of the accelerator pedal within a predetermined period after the amount of depression of the accelerator pedal becomes equal to or less than the first threshold. Sometimes, the control by the alarm control unit 164 and the brake control unit 168 is released.

  Suppressing the control by the alarm control unit 164 and the braking control unit 168 means releasing the alarm, the alarm brake, and the emergency brake.

  Here, when overtaking, the driver depresses the accelerator pedal strongly. Here, to depress the accelerator pedal strongly means to depress the accelerator pedal quickly, in other words, to depress the accelerator pedal so that the amount of increase of the accelerator pedal within a predetermined period is equal to or greater than a predetermined threshold. In such a case, since the host vehicle accelerates, generally, the distance between the host vehicle and the preceding vehicle decreases, and the relative speed also increases. Therefore, the alarm control by the alarm control unit 164 and the brake control by the brake control unit 168 are also performed. It tends to occur. However, this kind of acceleration was intentionally performed by the driver, and if an alarm is output or braking by automatic braking is performed up to such a case, the driver feels bothered by this or the traffic flow is reduced. It can be a cause of disturbance.

  In the present embodiment, when such an operation that the driver strongly depresses the accelerator pedal is performed after the driver once releases the accelerator pedal, it is clearly determined that the driver is intentionally accelerated, Release the alarm, alarm brake, and emergency brake. That is, in the present embodiment, the alarm / braking suppression unit 300 is provided, and after the accelerator pedal depression amount becomes equal to or less than the first threshold, the depression amount of the accelerator pedal within a predetermined period is equal to or more than the second threshold. Such a problem can be effectively avoided by suppressing the control by the alarm control unit 164 and the braking control unit 168. Incidentally, the case where the first threshold value is set to 0 corresponds to an operation in which the driver once releases the accelerator pedal. In practice, the first threshold value is set to 0 or a small value close to approximately 0.

  Next, an example of alarm and braking suppression processing in the present embodiment will be described with reference to FIG.

  When AEBS is turned on in step S10, alarm control by the alarm control unit 164 and braking control by the brake control unit 168 are performed in step S11.

  In step S12, the warning / braking suppression unit 300 determines whether or not the accelerator pedal depression amount is equal to or less than the first threshold value. In step S13, whether or not the accelerator pedal depression amount is equal to or greater than the second threshold value within a predetermined period (that is, Whether the amount of increase in depression of the accelerator pedal within a predetermined period has become equal to or greater than a predetermined threshold value). If a negative result is obtained in step S12 or step S13, the process returns to step S10. Thereby, in the state where AEBS is on, the alarm control and the braking control are continued until a positive result is obtained in both step S12 and step S13.

  On the other hand, if the alarm / braking suppression unit 300 obtains a positive result in both step S12 and step S13, the alarm / braking suppression unit 300 moves to step S14 and suppresses the alarm control and the brake control. Next, in step S15, the warning / braking suppression unit 300 determines whether or not the elapsed time t from the start of suppression is less than a predetermined time T1 (for example, 10 seconds). And when elapsed time t is less than time T1, it returns to step S14 and alarm control and braking control are suppressed.

  The processing of steps S12 and S13 will be described using the timing chart of FIG. In the example of FIG. 3, when the maximum depression amount of the accelerator pedal (accelerator pedal position when the accelerator pedal is fully depressed) is 100%, the first threshold value is 5% and the second threshold value is 95%. .

  As shown in FIG. 3A, the alarm / braking suppression unit 300 raises the accelerator release flag as shown in FIG. 3B when the accelerator pedal position falls below 5%, which is the first threshold value. The accelerator release flag is maintained in a state where the accelerator pedal position is raised for a predetermined period (1.5 seconds in the example) from the time t2 when the accelerator pedal position becomes 5% or more which is the first threshold again. On the other hand, as shown in FIG. 3C, the warning / braking suppression unit 300 raises the accelerator depression flag at time t3 when the accelerator pedal position becomes 95% or more which is the second threshold value. The warning / braking suppression unit 300 generates a suppression flag by taking the logical product of the accelerator release flag and the accelerator depression flag. In the example of FIG. 3, as shown in FIG. 3D, the suppression flag rises at time t <b> 3, so the alarm / brake suppression unit 300 suppresses alarm control and braking control from time t <b> 3.

In the present embodiment, it is presented that the following two conditions are provided as conditions for suppressing alarms and braking.
Condition 1. The amount of increase in depression of the accelerator pedal within a predetermined period is equal to or greater than a predetermined threshold (that is, the accelerator pedal is quickly depressed at a predetermined speed or more). In the example of FIG. 3, the threshold value TH0 of the accelerator pedal depression amount per unit time is (95% -5%) / 1.5 seconds, and the actual accelerator pedal depression amount per unit time is (95 % -5%) / (t3-t2). Therefore, in the example of FIG. 3, Condition 1 is satisfied because the actual depression amount of the accelerator pedal per unit time is equal to or greater than the threshold value TH0.
Condition 2. The operation of Condition 1 was performed after the accelerator was once released or almost released.

  By providing such conditions, alarms and braking can be suppressed only when the driver intentionally accelerates the host vehicle, and inadvertent suppression can be avoided.

  Further, as shown in FIG. 4, the second threshold value for suppression may be changed according to the position of the accelerator pedal. Specifically, the smaller the original accelerator pedal depression amount, the smaller the threshold value is set. This is based on the idea that when the original depression amount of the accelerator pedal is large, since the accelerator pedal has already been sufficiently depressed, the threshold for suppression may be reduced.

  As described above in detail, according to the present embodiment, alarm / brake control units 164 and 168 for controlling alarm and braking based on distance information and relative speed information between the host vehicle and the preceding vehicle, An alarm / brake suppression unit 300 that suppresses the control when the amount of depression of the accelerator pedal within a predetermined period becomes equal to or greater than a second threshold after the amount of depression of the accelerator pedal becomes equal to or less than a first threshold; By providing, alarms and braking that cause the driver to feel troublesome or disturb the traffic flow can be reduced.

  In the above-described embodiment, the case where both the alarm and the automatic brake (braking) are suppressed when the depression amount of the accelerator pedal within the predetermined period exceeds the second threshold is described. Alternatively, only one of automatic braking (braking) may be suppressed.

  In addition, each of the above-described embodiments is merely an example of actualization in carrying out the present invention, and the technical scope of the present invention should not be construed in a limited manner. That is, the present invention can be implemented in various forms without departing from the gist or the main features thereof.

  Each function of the braking force control device 160 described in the above embodiment can be realized by a computer program. Specifically, a CPU (Central Processing Unit) included in a computer copies a program stored in a storage device to a RAM (Random Access Memory), and sequentially reads instructions from the RAM and executes them. Each function described above is realized.

  The present invention can be applied to a braking force control device and a braking force control method for controlling alarm and braking based on the distance and relative speed between the host vehicle and the preceding vehicle.

DESCRIPTION OF SYMBOLS 100 Vehicle 120 Front vehicle detection part 140 Speed detection part 160 Braking force control apparatus 162 Collision allowance time calculation part 164 Alarm control part 166 Target deceleration calculation part 168 Braking control part 180 Warning part 200 Braking part 300 Warning / braking suppression part

Claims (4)

An alarm / brake control unit that executes alarm and / or braking control based on distance information and relative speed information between the host vehicle and the preceding vehicle;
An alarm / braking suppression unit that suppresses the control when the amount of depression of the accelerator pedal within a predetermined period becomes equal to or greater than a second threshold after the amount of depression of the accelerator pedal becomes equal to or less than a first threshold; ,
A braking force control device comprising: The first threshold is 0.
The braking force control apparatus according to claim 1. The second threshold value is larger as the amount of depression of the accelerator pedal is smaller.
The braking force control apparatus according to claim 1 or 2. An alarm / brake control step for executing alarm and / or braking control based on distance information and relative speed information between the host vehicle and the preceding vehicle;
An alarm / braking suppression step for suppressing the control when the depression amount of the accelerator pedal within a predetermined period becomes equal to or greater than a second threshold after the depression amount of the accelerator pedal becomes equal to or less than a first threshold; ,
A braking force control method including:

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