JP4869791B2 - Automatic braking control device - Google Patents

Description

  The present invention is used for large vehicles (trucks, buses) for transporting cargo and passengers.

  The electronic control of automobiles has progressed steadily, and events that have so far depended solely on the judgment of the driver have been carried out by onboard computers.

  As an example, the distance between the preceding vehicle and the host vehicle (inter-vehicle distance) is monitored by a radar, and when the inter-vehicle distance approaches abnormally, appropriate braking control is automatically performed to prevent a collision. Sometimes, there is an automatic braking control device that minimizes the damage (see, for example, Patent Document 1).

JP 2005-31967 A

  The above-described automatic braking control device has already been put into practical use in passenger cars, but it must be solved when a similar function is to be used for large vehicles (trucks, buses) for transporting cargo and passengers. There is a problem that must be done.

  In other words, large vehicles have an extremely large mass compared to passenger cars, and in addition to the driver's own safety, the safety of passengers and cargo must be ensured. It is difficult to achieve the intended purpose with simple simple braking control, and it is necessary to perform more advanced automatic braking control than in the case of passenger cars. However, since such means has not been established, automatic braking control devices for trucks and buses have not yet been put into practical use.

  The present invention has been made under such a background, and an object thereof is to provide an automatic braking control device that can realize automatic braking control in a truck or a bus.

  The present invention includes a control unit that automatically performs braking control based on a sensor output including a distance to an object in the traveling direction of the host vehicle without a driving operation, and the control unit is obtained from the sensor output. When the estimated time required for the object and the vehicle to be derived based on the relative distance and relative speed between the object and the vehicle is less than a predetermined distance is automatically less than a set value, It is an automatic braking control device provided with a gradual braking control means for performing gradual braking control for gradually increasing braking force or braking deceleration over a plurality of stages in a time series.

  The predicted time required for the object and the vehicle to be derived based on the relative distance and relative speed between the object and the vehicle is equal to or less than a predetermined distance is, for example, a collision between the object and the vehicle This is the estimated time required to do this (hereinafter referred to as TTC (Time To Collision)).

  Thereby, the braking control for gradually increasing the braking force or the braking deceleration can be performed over a plurality of stages, and the braking control suitable for large vehicles such as trucks and buses can be performed.

  Here, a feature of the present invention is that a sudden braking operation detecting means for detecting a sudden braking operation by a driver is provided, and the stepwise braking control means is configured to perform the sudden braking operation during execution of the stepwise braking control. When the braking operation detecting means detects a sudden braking operation by the driver, the braking operation detecting means is provided with a braking interruption means for stopping the stepwise braking control and executing braking by a predetermined braking force or braking deceleration.

  That is, the automatic braking control device of the present invention has the purpose of interpolating the lack of attention due to the driver's drowsiness or looking aside, and is usually suitable for such a situation (that is, the driver's lack of attention). Although the braking pattern is applied, if there is a sudden braking operation by the driver when performing automatic braking control, it is understood that the driver recognizes the necessity of sudden braking of the own vehicle, It is desirable to change to a braking pattern suitable for such a situation (that is, a state where the driver's attention is not lacking).

  Therefore, in the present invention, a means for detecting a sudden braking operation by the driver is provided, and when a sudden braking operation by the driver is detected during the execution of the stepwise braking control, a predetermined braking force or braking deceleration is used. Perform braking. The predetermined braking force or braking deceleration is, for example, the maximum braking force or braking deceleration that the host vehicle has.

  At this time, in the braking control according to the present invention, the sudden braking operation by the driver is not simply given priority over the automatic braking control as it is, but a predetermined (for example, maximum) sharper than the sudden braking operation performed by the driver. Braking control for exerting braking force or braking deceleration can be performed. That is, the braking interrupting means stops the stepwise braking control and executes braking with a predetermined braking force or braking deceleration according to the maximum braking force or braking deceleration increasing rate of the own vehicle. Means for increasing the braking force or braking deceleration may be provided.

  In addition, when the host vehicle speed is less than a predetermined value and the value taken by the steering angle or yaw rate is out of the predetermined range, a means for prohibiting activation of the stepwise braking control means can be provided.

  That is, the stepwise braking control performed by the automatic braking control device of the present invention is, for example, when the vehicle speed before starting the braking control is 60 km / h or more, and a large steering wheel operation such as when changing lanes or driving sharp curves is performed. Since it is assumed to be used in a state where it is not performed, the start of the stepwise braking control can be restricted in other traveling states.

  For example, if the vehicle speed before the start of braking control is less than 60 km / h, the vehicle has less kinetic energy, so there is no problem even if simple sudden braking control as conventionally applied to passenger cars is performed. Limit the start of stepwise braking control. Also, for example, if the steering angle before starting the braking control is + 30 ° or more or −30 ° or less, this means that the vehicle is changing lanes or driving in a sharp curve. Restrict. In this case, a yaw rate may be used instead of the steering angle.

  According to the present invention, automatic braking control in a truck or bus can be realized. In particular, the braking pattern can be changed depending on whether or not there is a sudden braking operation by the driver after the start of automatic braking control, and automatic braking control suitable for the situation at that time can be performed.

  An automatic braking control apparatus according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a control system configuration diagram of the present embodiment. FIG. 2 is a diagram showing a braking pattern at the time of idle loading that the braking control ECU has. FIG. 3 is a diagram showing brake pedal strokes during normal braking operation and sudden braking operation. FIG. 4 is a flowchart showing a sudden braking operation detection procedure in the sudden braking operation detection unit. FIG. 5 is a diagram showing the rate of increase in brake pressure during normal sudden braking and emergency braking. FIG. 6 is a diagram showing a braking pattern when emergency braking is interrupted in the warning braking stage. FIG. 7 is a diagram showing a braking pattern when emergency braking is interrupted in the enlarged region braking stage. FIG. 8 is a diagram showing a braking pattern when emergency braking is interrupted in the full-scale braking stage. FIG. 9 is a diagram showing a braking pattern when emergency braking is interrupted in full-scale braking. FIG. 10 is a diagram showing a braking pattern at the time of half product of the braking control ECU. FIG. 11 is a diagram showing a braking pattern at the time of fixed volume possessed by the braking control ECU. FIG. 12 is a diagram showing a full-scale braking pattern possessed by the braking control ECU. FIG. 13 is a flowchart showing a control procedure of a braking control ECU (Electric Control Unit) in a braking pattern at the time of idle product.

  As shown in FIG. 1, the braking control ECU 4, the gateway ECU 5, the meter ECU 6, the engine ECU 8, the axle weight meter 9, and the EBS (Electric Breaking System) _ECU 10 are connected to each other via a VehicleCAN (J1939) 7.

  The steering sensor 2, the yaw rate sensor 3, the vehicle speed sensor 13, and the brake operation sensor 14 are connected to the VehicleCAN (J1939) 7 via the gateway ECU 5, and the sensor information is taken into the braking control ECU 4. The brake control is performed by the EBS_ECU 10 driving the brake actuator 11. Note that the brake instruction to the EBS_ECU 10 is performed by the brake operation and braking control ECU 4 at the driver's seat (not shown). The brake information including information on the brake operation by the driver is also output from the EBS_ECU 10 and taken into the brake control ECU 4. The engine ECU 8 performs fuel injection amount control of the engine 12 and other engine control. Note that the injection amount control instruction to the engine ECU 8 is performed by the accelerator operation of the driver's seat. Further, the alarm display and buzzer sound output by the braking control ECU 4 are displayed on the display unit (not shown) of the driver's seat by the meter ECU 6. Since the control system related to steering other than the steering sensor 2 is not directly related to the present invention, the illustration is omitted.

  In this embodiment, as shown in FIG. 1, a millimeter wave radar 1 for measuring a distance from a preceding vehicle or a falling object such as a falling object in the traveling direction of the own vehicle, a steering sensor 2 for detecting a steering angle, This is an automatic braking control device including a braking control ECU 4 that automatically performs braking control based on sensor outputs such as a yaw rate sensor 3 for detecting the yaw rate and a vehicle speed sensor 13 for detecting the host vehicle speed without any driving operation. .

  The braking control ECU 4 automatically detects when the TTC derived based on the relative distance and relative speed between the object and the vehicle obtained from the sensor outputs from the millimeter wave radar 1 and the vehicle speed sensor 13 falls below a set value. Stepwise braking control. In this stepwise braking control, as shown in FIGS. 2, 10, and 11, the braking force is gradually increased over three stages in time series.

  In the example of FIG. 2B, the braking control ECU 4 first applies braking of about 0.1 G from TTC 2.4 seconds to 1.6 seconds in the first stage marked “alarm”. At this stage, the so-called sudden braking is not yet applied, and the stop lamp is lit to notify the following vehicle that the sudden braking will be performed. Subsequently, in the second stage labeled “enlarged area braking”, braking of about 0.3 G is applied from TTC 1.6 seconds to 0.8 seconds. Finally, in the third stage, marked as “full-scale braking”, the maximum braking (about 0.5 G) is applied from TTC 0.8 seconds to 0 seconds.

  Here, a feature of the present embodiment is that a sudden braking operation detection unit 40 that detects a sudden braking operation by the driver is provided, and the braking control ECU 4 performs the sudden braking operation during the execution of the stepwise braking control. When the detection unit 40 detects a sudden braking operation by the driver, the stepwise braking control is stopped and braking is executed with a predetermined braking force. In this embodiment, the predetermined braking force is the maximum braking force that the host vehicle has. This maximum braking force corresponds to the braking force of “full-scale braking” in the stepwise braking control.

  The driver's braking operation acts as a brake instruction to the EBS_ECU 10, and normally, the EBS_ECU 10 appropriately adjusts the braking force of the brake actuator 11 in proportion to the amount of depression of the driver's brake pedal. In this embodiment, when the sudden braking operation detection unit 40 detects the driver's sudden braking operation after the stepwise braking control is started, the braking control ECU 4 increases the maximum braking force with respect to the EBS_ECU 10. Instructs emergency braking at a rate.

  Here, the sudden braking operation detection procedure in the sudden braking operation detection unit 40 will be described with reference to FIGS. 3 and 4. In FIG. 3, the horizontal axis represents time (seconds) and the vertical axis represents brake pedal stroke (mm). Comparing the normal braking operation of FIG. 3A and the sudden braking operation of FIG. 3B, the time required for the brake pedal stroke to reach the maximum stroke from, for example, 0 (mm) is shown in FIG. It can be seen that the sudden braking operation shown in FIG. 3) is significantly shorter than the normal braking operation shown in FIG. Therefore, as shown in FIG. 4, the sudden braking operation detection unit 40 monitors the brake pedal stroke from the brake operation information of the brake operation sensor 14 (S1), and the brake pedal stroke reaches a maximum stroke from 0 (mm), for example. When the time until is less than or equal to the threshold value (S2), it is determined that the sudden braking operation is detected (S3).

Next, the brake pressure increase rate when the EBS_ECU 10 drives the brake actuator 11 will be described with reference to FIG. The brake pressure increase rate is reflected in the braking force increase rate. In FIG. 5, the horizontal axis represents time (seconds), and the vertical axis represents brake pressure (kg / cm ² ). The brake pressure increase rate during normal sudden braking shown in FIG. 5A is the brake pressure increase rate due to the driver's sudden braking operation. On the other hand, the brake pressure increase rate during emergency braking shown in FIG. 5 (b) is a steeper brake pressure increase rate than the driver's sudden braking operation.

  In the present embodiment, when the sudden braking operation detection unit 40 detects the driver's sudden braking operation after the start of the stepwise braking control, the braking control ECU 4 instructs the EBS_ECU 10 regardless of the brake pedal depression amount of the driver. The brake actuator 11 is instructed to be driven at the brake pressure increase rate shown in FIG.

  Next, an example of a braking pattern when a driver's sudden braking operation is detected after the start of the stepwise braking control will be described with reference to FIGS. 6, 7, 8, and 9. In the example of FIG. 6, “alarm” braking control is started from TTC = 2.4 seconds, and immediately after that, an emergency braking operation by the driver is detected and emergency braking is started. In the example of FIG. 7, “extended area” braking control is started from TTC = 1.6 seconds, and immediately after that, a sudden braking operation by the driver is detected and emergency braking is started. In the example of FIG. 8, “full-scale braking” control is started from TTC = 0.8 seconds, and immediately after that, a sudden braking operation by the driver is detected and emergency braking is started. When emergency braking was not started, stepwise braking control as shown by the broken line was scheduled to be executed.

  As will be described later, when the vehicle speed before the start of the braking control is less than 60 km / h and 15 km / h or more, the stepwise braking control is not performed, but only the full-scale braking control is performed. . In such a case, in the example of FIG. 9, “full-scale braking” control is started from TTC = 0.8 seconds, and immediately after that, a sudden braking operation by the driver is detected and emergency braking is started.

  In this embodiment, as shown in FIGS. 2, 10, and 11, the braking pattern selection unit 41 selects a braking pattern according to the loaded cargo or the weight of the passenger. As a selection method, the braking pattern storage unit 42 of the braking control ECU 4 stores a plurality of control patterns for “empty product”, “half product”, and “constant product”, and the braking pattern selection unit 41 This can be realized by selecting a braking pattern that matches (or approximates) these braking patterns according to the weight. The weight information of the loaded cargo and passengers is obtained by the axle weight meter 9 shown in FIG. 1 and is taken into the braking control ECU 4. If the equal braking forces are compared with each other, the braking distance increases as the weight of the loaded cargo or passenger increases. Therefore, the start timing of the automatic braking control becomes earlier as the weight of the loaded cargo or passenger increases.

  In the following description, the preceding vehicle will be described, but the automatic braking control device of this embodiment is also effective for falling objects on the road.

  Further, when the host vehicle speed is less than 60 km / h and the steering angle is not less than +30 degrees or not more than -30 degrees, the braking control ECU 4 prohibits the start of the stepwise braking control. A yaw rate may be used instead of the steering angle.

  In other words, the stepwise braking control performed by the automatic braking control device of this embodiment is such that the host vehicle speed before starting the braking control is 60 km / h or more, and a large steering wheel operation such as when changing lanes or driving sharp curves is performed. Since it is assumed that the vehicle is not used, it is possible to limit the start of the stepwise braking control in other driving conditions.

  Also, if the vehicle speed before the start of braking control is less than 60 km / h, the vehicle has less kinetic energy, so there is no problem even if simple sudden braking control as conventionally applied to passenger cars is performed. Since the usefulness of performing stepwise braking control is low, the activation of stepwise braking control is limited. Alternatively, if the steering angle before the start of the braking control is +30 degrees or more or -30 degrees or less, this means that the vehicle is changing lanes or traveling sharply. Restrict startup of. In this case, a yaw rate may be used instead of the steering angle.

  In the present embodiment, when the vehicle speed before the start of the braking control is less than 60 km / h and not less than 15 km / h, the stepwise braking control is not performed, but as shown in FIG. 12, FIG. Only the full-scale braking control shown in FIG. 11 is performed. When only such full-scale braking control is performed, braking control equivalent to conventional automatic braking control used for passenger cars can be applied. In addition, when applying such automatic braking control equivalent to the conventional one, there is no need to determine whether or not the vehicle is changing lanes or traveling sharply.

  Next, the operation of the automatic braking control apparatus according to the present embodiment when the braking pattern at the time of idle loading shown in FIG. 2 is selected will be described with reference to the flowchart of FIG. FIG. 13 will be described by taking a braking pattern at the time of idle product (FIG. 2) as an example, but the procedure of the flowchart of FIG. 13 is also followed at the time of half product (FIG. 10) or constant product (FIG. 11). As shown in FIG. 13, the braking control ECU 4 measures and monitors the inter-vehicle distance from the preceding vehicle and the vehicle speed of the preceding vehicle by the millimeter wave radar 1. Further, the vehicle speed is measured by the vehicle speed sensor 13 and monitored. Further, the weight of the loaded cargo and passengers is measured and monitored by the axle weight meter 9. The sudden braking operation detection unit 40 of the braking control ECU 4 monitors the sudden braking operation from the brake operation information of the brake operation sensor 14. The braking pattern selection unit 41 of the braking control ECU 4 selects in advance one of the braking patterns (FIGS. 2, 10, and 11) based on the measurement result of the weight (S11). The following description is an example in which the braking pattern in FIG. 2 is selected.

Subsequently, the braking control ECU 4 calculates TTC from the inter-vehicle distance, the own vehicle speed, and the vehicle speed of the preceding vehicle (S12). The calculation method is
Distance between vehicles / (Self-vehicle speed-Vehicle speed of the preceding vehicle)
It is. The braking control ECU 4 has a vehicle speed before starting braking control of 60 km / h or more (S13), a steering angle before starting braking control is +30 degrees or less and -30 degrees or more (S14), and TTC is shown in FIG. If it is in the region of (1) shown in (a) (S15), “alarm” braking control is executed (S20). Here, when the sudden braking operation detection unit 40 detects a sudden braking operation by the driver, (S18) The “alarm” braking control is stopped and emergency braking is executed (S19). This is as shown in FIG. If the TTC is in the region (2) shown in FIG. 2A (S16), the “enlarged region braking” control is executed (S21). Here, the sudden braking operation detection unit 40 is operated by the driver. When a sudden braking operation is detected (S18), the “enlarged area” braking control is stopped and emergency braking is executed (S19). This is as shown in FIG. If the TTC is in the region (3) shown in FIG. 2A (S17), the “full-scale braking” control is executed (S22). When a braking operation is detected (S18), the "full-scale braking" control is stopped and emergency braking is executed (S19). This is as shown in FIG.

  Further, if the host vehicle speed before starting the braking control is less than 60 km / h and 15 km / h or more (S13, S23), and the TTC is in the region (4) shown in FIG. 2C (S24), the braking control ECU 4 Notifies the driver that the relative distance from the preceding vehicle is short (S25). Notification is performed by warning display or buzzer sound. Further, if the TTC is in the region (5) shown in FIG. 2C (S26), the “full-scale braking” control is executed (S26). When a braking operation is detected (S18), the "full-scale braking" control is stopped and emergency braking is executed (S19). This situation is as shown in FIG.

  Here, FIGS. 2, 10, and 11 will be described. The straight lines c, f, i in FIGS. 2, 10, and 11 are called steering avoidance limit straight lines. Further, curves B, D, and F in FIGS. 2, 10, and 11 are called braking avoidance limit curves.

  That is, the steering avoidance limit straight line is a straight line indicating a limit at which a collision can be avoided by a steering operation within a predetermined TTC in the relationship between one relative distance to the obstacle and one relative speed with the obstacle. The braking avoidance limit curve is a curve indicating a limit at which a collision can be avoided by a braking operation within a predetermined TTC in the relationship between one relative distance to the obstacle and one relative speed with the obstacle.

  2, 10, and 11, a collision can no longer be avoided by a steering operation or a braking operation in a region where both of the lower sides of these straight lines or curves are involved.

  For example, in the case of the empty product in FIG. 2, the straight line c has TTC set to 0.8 seconds. In the present embodiment, a straight line b when the TTC is 1.6 seconds is provided above the steering avoidance limit straight line c, and a straight line a when the TTC is 2.4 seconds is provided. Further, a curve A with TTC set at 1.6 seconds is provided above the braking avoidance limit curve B with TTC set at 0.8 seconds.

  The initial state of the vehicle has a relative distance and a relative speed with respect to the obstacle indicated by the black point G in FIG. When the host vehicle speed before the start of braking control is 60 km / h or more, the relative distance gradually decreases, and when the vehicle reaches the position of the straight line a, the alarm mode is set (area (1)). In the alarm mode, braking of about 0.1 G is applied from TTC 2.4 seconds to 1.6 seconds. During this period, it is meaningful to turn on the stop lamp and inform the subsequent vehicle of braking. When the relative speed further decreases and reaches the position of the straight line b, the expansion area braking mode is set (area (2)). In the enlarged area braking mode, braking of about 0.3 G is applied from TTC 1.6 seconds to 0.8 seconds. When the position of the straight line c is reached, the full braking mode is set (area (3)). In the full-scale braking mode, the maximum braking force (about 0.5G) is applied from TTC 0.8 seconds to 0 seconds. According to the calculation in step S12 in FIG. 13, a collision occurs at this time. However, the actual TTC is longer than the calculation result of step S12.

  In other words, in the calculation of TTC in the automatic braking control device targeted by the present invention, precise distance measurement and complicated calculation processing are omitted as much as possible, and a general-purpose simple distance measurement device (for example, millimeter wave radar) or a calculation device is used. It is assumed that. Such considerations are useful for keeping vehicle manufacturing costs or maintenance costs low.

  Therefore, strictly speaking, the preceding vehicle and the subject vehicle, which are the objects, are performing a uniform acceleration motion by braking (deceleration), and therefore the TTC calculation must also be calculated based on the uniform acceleration motion. By calculating the TTC as simply performing constant velocity motion, precise distance measurement and complicated arithmetic processing are omitted.

  In addition, by performing a calculation that is regarded as such a constant velocity motion, the calculated TTC value becomes smaller than the actual TTC value. There is no hindrance.

  Further, when the host vehicle speed before starting the braking control is 15 km / h or more and less than 60 km / h, the relative distance is gradually shortened, and when the vehicle reaches the position of the straight line b, the notification mode is set (region (4)). . In the notification mode, the driver is notified that the relative distance to the obstacle is shortened by an alarm display or a buzzer sound. In the notification mode, TTC starts from 1.6 seconds. Note that the notification mode can be maintained even in the next full-scale braking mode. When the position of the straight line c is reached, the full braking mode is set (area (5)). In the full-scale braking mode, the maximum braking force (about 0.5G) is applied from TTC 0.8 seconds to 0 seconds.

  FIG. 10 shows an example at half load, and FIG. 11 shows an example at fixed load. However, if equal braking forces are compared, the braking distance increases as the weight of loaded cargo and passengers increases. The avoidance limit straight line and the braking avoidance limit curve also move upward in the figure. Thereby, the area of area | region (1), (2), (3), (4), (5) becomes large according to the weight of a loaded cargo or a passenger.

  2 correspond to the straight lines d to f in FIG. 10 and the straight lines g to i in FIG. 11, and the curves A and B in FIG. 2 are the curves C and D in FIG. 10 and the curve E in FIG. , F, and the black point G in FIG. 2 corresponds to the black point H in FIG. 10 and the black point I in FIG.

  In this embodiment, as shown in FIGS. 6 to 8, the driver suddenly stops during the stepwise braking control at the time of empty product, half product, and constant product shown in FIGS. When the braking operation is detected, the stepwise braking control being executed is stopped and emergency braking is executed. Further, when the host vehicle speed before starting the braking control is 15 km / h or more and less than 60 km / h, as shown in FIG. 9, when a sudden braking operation by the driver is detected during the “full-scale braking” control. The “full-scale braking” control being executed is stopped and emergency braking is executed.

  ADVANTAGE OF THE INVENTION According to this invention, the automatic braking control in a truck or a bus | bath can be implement | achieved, and it can contribute to traffic safety. In particular, the braking pattern can be changed depending on whether or not there is a sudden braking operation by the driver after the start of automatic braking control, and automatic braking control suitable for the situation at that time can be performed.

The control system block diagram of a present Example. The figure which shows the braking pattern at the time of the idle product which braking control ECU has. The figure which shows the brake pedal stroke at the time of normal braking operation and sudden braking operation. The flowchart which shows the sudden braking operation detection procedure in the sudden braking operation detection part. The figure which shows the brake pressure increase rate at the time of normal sudden braking and emergency braking. The figure which shows the braking pattern when emergency braking interrupts in an alarm braking step. The figure which shows the braking pattern when emergency braking interrupts in an expansion area | region braking step. The figure which shows the braking pattern when emergency braking interrupts in the full-scale braking stage. The figure which shows the braking pattern when emergency braking interrupts in full-scale braking. The figure which shows the braking pattern at the time of the half product which braking control ECU has. The figure which shows the braking pattern at the time of the fixed volume which braking control ECU has. The figure which shows the full-scale braking pattern which braking control ECU has. The flowchart which shows the control procedure of braking control ECU in the braking pattern at the time of an unloaded.

Explanation of symbols

1 Millimeter wave radar 2 Steering sensor 3 Yaw rate sensor 4 Braking control ECU
5 Gateway ECU
6 Meter ECU
7 VehicleCAN (J1939)
8 Engine ECU
9 Shaft weigher 10 EBS_ECU
DESCRIPTION OF SYMBOLS 11 Brake actuator 12 Engine 13 Vehicle speed sensor 14 Brake operation sensor 40 Sudden braking operation detection part 41 Brake pattern selection part 42 Brake pattern memory | storage part

Claims (4)

Control means for automatically performing braking control without a driving operation based on a sensor output including a distance from an object in the traveling direction of the host vehicle,
The control means calculates an estimated time required for the object and the vehicle to collide based on a relative distance and a relative speed between the object and the vehicle obtained from the sensor output , and the estimated time There comprises a stepwise brake control means for automatically phased braking control when below a set time,
This stepwise braking control means is a braking control means for increasing the braking force or the braking deceleration in three stages in time series including the first braking stage, the second braking stage, and the third braking stage.
The braking in the first braking stage, the second braking stage, and the third braking stage is such that a constant amount of braking force or braking deceleration is continuously given,
When the predicted time falls below a preset predetermined time before a limit time that can avoid a collision by a braking operation, the braking of the first braking stage is continuously applied until a limit time that can avoid a collision by the braking operation,
When the predicted time is less than a limit time that can avoid a collision by the braking operation, the braking of the second braking stage is continuously given until a limit time that can avoid a collision by a steering operation,
An automatic braking control device that continuously applies braking in a third braking stage when the predicted time is less than a time limit for avoiding a collision by a steering operation ,
A sudden braking operation detecting means for detecting a sudden braking operation by the driver is provided,
The stepwise braking control means stops the stepwise braking control when the sudden braking operation detecting means detects a sudden braking operation by the driver during the execution of the stepwise braking control, and a predetermined braking force or An automatic braking control device comprising braking interruption means for executing braking by braking deceleration.   2. The automatic braking control device according to claim 1, wherein the predetermined braking force or braking deceleration is a maximum braking force or braking deceleration that the host vehicle has.   When interrupting the stepwise braking control and executing braking with a predetermined braking force or braking deceleration, the interrupting means uses the maximum braking force or braking deceleration increasing rate of the host vehicle to increase the braking force or 3. The automatic braking control device according to claim 1, further comprising means for increasing the braking deceleration. 4. The automatic operation according to claim 1, further comprising means for prohibiting start of the stepwise braking control means when the host vehicle speed is less than a predetermined value or the value of the steering angle or yaw rate is outside the predetermined range. Braking control device.

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