JP5287312B2 - Vehicle braking device - Google Patents

Description

  The present invention relates to an actual collision detecting means for detecting a collision of a vehicle, an electric parking brake device for braking a wheel by driving an electric brake mechanism, and an electric parking brake device based on collision detection information by the actual collision detecting means. And a control means for controlling the operating state of the vehicle.

  2. Description of the Related Art Conventionally, there has been known a vehicle braking device that prevents a secondary collision of a vehicle by operating an electric parking brake device independently of an occupant's braking operation at the time of a vehicle collision (for example, Patent Document 1). reference).

The vehicle braking apparatus includes a collision sensor that detects a collision of the vehicle and a control device that controls the operation of the electric brake device based on a signal from the collision sensor, and the collision is detected by the collision sensor. Sometimes, the direction of the collision (primary collision) is determined based on the detection signal to estimate the moving direction of the host vehicle due to the primary collision. If the traffic situation in this estimated direction is estimated based on information from the camera, radar, etc., and it is determined from this estimation result that the possibility of a secondary collision of the vehicle is high, the wheel control of the electric brake device is On the other hand, when it is determined that the possibility of a secondary collision of the vehicle is low while increasing the power, the wheel braking force of the electric brake device is reduced.
JP 2003-081074 A

  By the way, in general, when a vehicle is collided with another vehicle (especially when colliding from the rear), there are many cases where the collision is unexpected for the occupant. The damage received increases. For this reason, in the case where the vehicle collides with another vehicle while the vehicle is stopped, the request for prevention of secondary collisions as well as the request for occupant protection is particularly strong.

  However, in the conventional vehicle braking device disclosed in Patent Document 1, when a vehicle collides with another vehicle (primary collision) while the vehicle is stopped, there is a high possibility of a secondary collision of the vehicle after the collision. Therefore, when the primary collision is a heavy collision, for example, a large rebound force acts on the passenger in the passenger compartment. In addition, if the possibility of a secondary collision of the vehicle is low after the primary collision, the wheel braking force of the vehicle is reduced. For example, when the primary collision is a heavy collision, At the time of the collision, the wheel braking force is insufficient and a large impact (hereinafter referred to as initial impact) is applied to the occupant in the passenger compartment, so there is room for improvement from the viewpoint of occupant protection.

  Further, in the above conventional vehicle braking device, since the brake device is operated after the collision is detected by the collision sensor, it is possible to sufficiently secure the braking force of the brake device at the time of the collision and immediately after that. There is a problem that it cannot be done, and there is room for improvement from the viewpoint of secondary collision prevention and occupant protection.

  The present invention has been made in view of the above points, and an object of the present invention is to provide an actual collision detection unit that detects a vehicle collision and an electric parking brake that performs wheel braking by driving an electric brake mechanism. A device and a control method for controlling the operating state of the electric parking brake device based on the collision detection information by the actual collision detection unit are devised for the configuration and the control method. Thus, in a case where the vehicle collides with an object approaching the vehicle while the vehicle is stopped, there is an attempt to reliably protect passengers in the vehicle compartment while preventing secondary collision of the vehicle.

In order to achieve the above object, according to the present invention, the braking force increase control for increasing the wheel braking force of the EPB device is executed before the collision between the vehicle and the object approaching the vehicle, and the EPB after the collision occurs. Control means for performing impact degree corresponding control for controlling the wheel braking force of the device in accordance with the magnitude of impact acceleration at the time of the collision, and the control means has a rudder angle detected by the rudder angle detection means greater than a predetermined angle In some cases, execution of the impact response control is prohibited, or when the presence of an occupant is not detected by the occupant detection means, execution of the impact response control is prohibited .

  Specifically, in the invention of claim 1, an actual collision detecting means for detecting a collision of the vehicle, and an electric parking brake device for braking the wheels of the vehicle by operating an electric brake mechanism driven by an electric actuator; The present invention is directed to a vehicle braking device including control means for controlling the operation of the electric parking brake device based on collision detection information obtained by the actual collision detection means.

And a collision prediction means for detecting an object approaching the vehicle and detecting whether or not the object is predicted to collide with the vehicle; and a collision at the time of collision of the vehicle with the object An impact degree acquisition means for acquiring acceleration by prediction or detection, and the control means predicts a collision between the vehicle and the object by the collision prediction means when the vehicle is stopped. When this occurs, the braking force increase control for operating the electric parking brake device in the direction in which the wheel braking force increases is executed, and after the collision prediction by the collision prediction unit, the vehicle and the target are detected by the actual collision detection unit. When a collision with an object is detected, the operation of the electric parking brake device after the detection is detected by the collision acceleration at the time of the collision acquired by the impact level acquisition means. Of being configured to perform a degree of impact corresponding control for controlling according to the magnitude, further comprising a steering angle detecting means for detecting a steering angle of the wheels, further said control means detected by the steering angle detection means When the steered angle is equal to or greater than a predetermined angle, the execution of the impact degree correspondence control is prohibited .

  According to this configuration, when there is an object (such as another vehicle) that is predicted to collide with a stopped vehicle, an electric parking brake device (hereinafter referred to as an EPB device) is applied before the object collides with the vehicle. The wheel braking force of the EPB device at the time of a collision between the object and the vehicle can be sufficiently increased. Accordingly, it is possible to reduce the initial impact that acts on the passenger in the vehicle compartment at the time of the collision and protect the passenger, and it is possible to reliably prevent the secondary collision of the vehicle.

  In addition, after the object collides with the vehicle, the wheel braking force of the EPB device is controlled according to the magnitude of the collision acceleration at the time of the collision, thereby controlling the rebound force received by the occupant after the collision due to the reaction of the collision Thus, the occupant can be surely protected.

  In general, since the EPB device is an independent brake device that operates independently of the occupant's stepping operation on the foot pedal, the operation reliability is high. Therefore, at the time of a collision in which a large impact is applied to the EPB device itself and immediately after the collision However, the EPB device can be reliably operated to further prevent the secondary collision and protect the occupant.

Further, when the rudder angle detected by the rudder angle detection means is greater than or equal to a predetermined angle, the execution of the impact degree control is prohibited. By executing the corresponding control and reducing the braking force, it is possible to reliably prevent the vehicle A from spinning or jumping out to the oncoming lane, and to ensure the occurrence of a secondary collision of the vehicle. Can be prevented.

According to a second aspect of the present invention, an actual collision detecting means for detecting a collision of the vehicle, an electric parking brake device for braking the wheels of the vehicle by operating an electric brake mechanism driven by an electric actuator, and the actual collision detection described above. And a control means for controlling the operation of the electric parking brake device on the basis of collision detection information by the means for detecting an object approaching the vehicle and detecting the object approaching the vehicle A collision prediction means for detecting whether or not the vehicle is predicted to collide with the vehicle, and an impact degree acquisition means for acquiring a collision acceleration at the time of a collision with the object in the vehicle by prediction or detection, When the vehicle is stopped, the control means is configured to detect a collision between the vehicle and the object when the collision prediction means predicts a collision. A braking force increase control for operating the electric parking brake device in a direction in which the wheel braking force increases is performed, and after the collision prediction by the collision prediction unit, the actual collision detection unit causes a collision between the vehicle and the object. Is detected, and the operation of the electric parking brake device after the detection is configured to perform impact degree corresponding control for controlling the operation according to the magnitude of the collision acceleration at the time of the collision acquired by the impact level acquisition means. Occupant detection means for detecting whether or not an occupant is present in the vehicle interior of the vehicle, and the control means is configured to detect the impact when no occupant is detected by the occupant detection means. It is assumed that execution of the degree correspondence control is prohibited.

According to this configuration, it is possible to prevent the wheel braking force of the EPB device 15 from being unnecessarily reduced by performing the impact degree control after the occurrence of the collision until there is no need for passenger protection. Thereby, the secondary collision of a vehicle can be prevented more reliably.

According to a third aspect of the present invention, in the first or second aspect of the invention, the impact degree corresponding control is performed when the impact acceleration obtained by the impact degree obtaining unit is equal to or greater than a predetermined value and less than a predetermined value. In comparison, the electric parking brake device is operated so as to reduce the wheel braking force of the electric parking brake device.

  According to this configuration, the wheel braking force of the EPB device after the collision is lower at the time of a heavy collision in which the impact acceleration is equal to or greater than a predetermined value, as compared to a light collision at which the impact acceleration is less than the predetermined value. Thereby, at the time of a heavy collision, it is possible to prevent a large rebound force from acting on the occupant by excessively increasing the wheel braking force, and to more reliably protect the occupant of the vehicle.

According to a fourth aspect of the present invention, in the third aspect of the present invention, the electric parking brake device is configured to be capable of switching a wheel braking force between a first braking force and a second braking force larger than the first braking force. In the impact degree control, the wheel braking force of the electric parking brake device is changed to the first braking force when the impact acceleration obtained by the impact degree obtaining means is not less than the predetermined value. When the impact acceleration is less than the predetermined value, the electric parking brake device is operated so that the wheel braking force of the electric parking brake device becomes the second braking force.

According to this configuration, since the wheel braking force of the EPB device is set to only two stages of the first braking force and the second braking force, the configuration can be simplified and the cost can be reduced. Further, the impact correspondence control can be easily realized only by switching between these two settings, and therefore the same effect as that of the invention of claim 3 can be obtained with certainty.

According to a fifth aspect of the present invention, in the braking device for a vehicle according to the fourth aspect , the braking force increase control is performed such that a collision between the vehicle and the object is predicted by the collision prediction means while the vehicle is stopped. In this case, when the wheel braking of the electric parking brake device is released or the wheel braking force is the first braking force, the wheel braking force of the electric parking brake device is directed toward the second braking force. The electric parking brake device is operated in the increasing direction.

  According to this configuration, the wheel braking force of the electric parking brake device at the time of a collision can be increased as much as possible, and the reduction of the initial impact received by the occupant and the prevention of the secondary collision can be further ensured.

  As described above, according to the braking device for a vehicle of the present invention, in a case where the vehicle collides with an object approaching the vehicle while the vehicle is stopped, an occupant in the vehicle interior can be reliably prevented while preventing a secondary collision of the vehicle. Can be protected.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows a vehicle A equipped with a braking device 100 according to an embodiment of the present invention, where 1 is a vehicle body, 2 is a hydraulic brake mechanism individually disposed on four front and rear wheels 4, , A master cylinder that generates hydraulic pressure according to the depression force of the brake pedal 5 of the occupant and supplies it to the hydraulic brake mechanism 2, 6 is a booster that boosts the depression force of the brake pedal 5, and 7 is the hydraulic brake mechanism 2. A pressurizing unit capable of pressurizing the hydraulic pressure supplied to the vehicle, 8 is an SCS controller for controlling the operation of the pressurizing unit 7 to individually control the braking force on each wheel 3, and 9 is disposed on the rear wheel 3R. The electric brake mechanism 10 is an EPB controller for controlling the operation of the electric brake mechanism 9, 11 is a parking switch for manually switching on / off the electric brake mechanism 9, and 12 is a steering switch. Grayed, 13 is an accelerator pedal. The brake pedal 5, the master cylinder 4, and the hydraulic brake mechanism 2 constitute a foot brake device 14, and the electric brake mechanism 9 and the EPB controller 10 are referred to as an electric parking brake device 15 (EPB (Electric Parking Brake) device). 3), and the pressurizing unit 7 and the SCS controller 8 constitute the SCS device 16.

  Further, 17 is an engine having a plurality of cylinders, and 18 is an ECU 18 that controls the operation of the engine 17 and performs overall traveling control of the vehicle A in cooperation with the controllers 8 and 10. The output rotation of the engine 17 is shifted by an automatic transmission (AT) (not shown) and transmitted to drive wheels (rear wheels 3R in this embodiment) by a drive shaft or the like.

  As shown in FIG. 2, the booster 6 has a movable wall 6a movable in the booster axial direction in conjunction with the brake pedal 5, and a negative pressure chamber 6b and an atmospheric chamber 6c partitioned by the movable wall 6a. Is used to boost the depressing force of the brake pedal 5. A vacuum pump (not shown) driven by the engine 17 is connected to the negative pressure chamber 6b, thereby reducing the pressure in the negative pressure chamber 6b and increasing the boosting action of the booster 6.

  The hydraulic brake mechanism 2 provided on each wheel 3 is connected to the master cylinder 4 by a hydraulic line 19, and the hydraulic brake mechanism 2 is activated in response to the depression of the brake pedal 5 by an occupant. A braking force is applied to the wheel 3.

  Specifically, each of the hydraulic brake mechanisms 2 has the same configuration, and as shown in FIG. 2, a rotor disk 21 mounted integrally with each wheel 3 and a rotor disk 21. And a caliper 22 for applying a braking force. The caliper 22 includes a caliper main body 26 disposed across the rotor disk in a bowl shape, an outer brake pad 23 and an inner brake disposed on both sides of the rotor disk 21 inside the caliper main body 26. And a pad 24. A piston 25 that can move in the axial direction of the rotor disk 21 is disposed on one side surface of the inner brake pad 24. The piston 25 is slidable in a cylinder hole 26a formed in the caliper body 26. It is inserted. The hydraulic pressure line 19 is connected to the cylinder hole 26a, and when an occupant steps on the brake pedal 5, hydraulic pressure is supplied from the hydraulic pressure line 19 to the cylinder hole 26a and the piston 25 moves forward. When the piston 25 moves forward, the inner brake pad 24 is pressed against one side of the rotor disk 21, and the caliper body 26 moves so as to press the outer brake pad 23 against the rotor disk 21 by the reaction force. As a result, the rotor disk 21 is sandwiched between the pads 23 and 24, and a braking force is applied to each wheel 3.

  The pressurizing unit 7 includes a hydraulic pump 35 provided in a first branch pipe 30 that is branched and connected to the hydraulic pipe 19, and the hydraulic pump 35 that can be intermittently connected to the hydraulic pipe 19. A pressurizing valve 32 provided in the first branch line 30, a return valve 33 provided in the second branch line 31 branched and connected to the hydraulic pressure line 19, and a brake for detecting the hydraulic pressure in the hydraulic pressure line 19 And a hydraulic pressure sensor 69. Each of the valves 32 and 33 is an electromagnetic open / close valve, and the hydraulic pump 35 is an electric pump using an electric motor (not shown) as a drive source. Operation control of these valves 31 and 32 and the hydraulic pump 35 is performed by the SCS controller 8. The hydraulic pump 35 operates with power supplied from an alternator (not shown) while the engine 17 is operating, and operates with power supplied from an in-vehicle battery (not shown) while the engine 17 is stopped. .

  Although the electric brake mechanism 9 employs a disc brake structure as in the hydraulic brake mechanism 2, the forward / backward movement of the piston 42 is not a linear motion conversion by hydraulic pressure but a rotation-linear motion via the screw mechanism 41. It differs from the hydraulic brake mechanism 2 in that it is realized by conversion. That is, a male threaded portion 43 is formed at one shaft end (shaft end opposite to the inner brake pad side) of the piston 42 used in the electric brake mechanism 9, and the piston 42 has the male threaded portion. 43 is supported by being screwed into a female screw portion 45 formed on the inner peripheral surface of the annular member 44. A gear surface 47 that meshes with the pinion gear 46 is formed on the outer peripheral surface of the annular member 44, and the pinion gear 46 is attached to the output shaft of the electric motor 48 so as to rotate together. The annular member 44 is restricted from moving in the piston axial direction (left-right direction in the figure) by a restriction member (not shown). Therefore, even when the electric motor 48 is driven to rotate, the annular member 44 is not a piston. With the axial position fixed, the pinion gear 46 is rotationally driven. As a result, the piston 42 screwed into the inner peripheral surface of the annular member 44 moves in the axial direction. Then, the piston 42 can be moved forward and backward by rotating the electric motor 48. The operation control of the electric motor 48 is performed by the EPB controller 10.

  As shown in FIG. 3, the ECU 18 includes a brake lamp switch 61, an accelerator sensor 62, a yaw rate sensor 63, a steering angle sensor 64, a lateral acceleration sensor 65, a wheel speed sensor 66, and an engine rotation speed sensor 67. The gradient sensor 68, the brake fluid pressure sensor 69, the radar 70, the collision sensor 71, the occupant sensor 72, and the parking switch 11 are connected to be able to exchange signals. The ECU 18 receives input signals from the sensors and controls the operation of the engine 17 and outputs necessary signals to the EPB controller 10 and the SCS controller 8.

  The brake lamp switch 61 detects a depression operation of the brake pedal 5 by an occupant and outputs a detection signal thereof. The accelerator sensor 62 outputs a signal corresponding to the amount of depression of the accelerator pedal 13. The yaw rate sensor 63 outputs a signal corresponding to the yaw rate of the vehicle A. The steering angle sensor 64 outputs a signal related to the absolute steering angle of the steering 12 (actual steering angle based on the steering angle position when going straight). The lateral acceleration sensor 65 outputs a signal related to the acceleration in the lateral direction (width direction) of the vehicle A. The wheel speed sensor 66 outputs a signal corresponding to the rotational speed of each wheel 3. The engine rotation speed sensor 67 outputs a signal corresponding to the rotation speed of the engine 17. The gradient sensor 68 outputs a signal corresponding to the gradient (tilt angle) of the road surface on which the vehicle A is stopped. The brake fluid pressure sensor 69 outputs a signal corresponding to the brake fluid pressure in the fluid pressure line 19.

  The radar 70 scans and transmits a millimeter wave to the rear of the vehicle within a predetermined angle range, and also transmits a vehicle based on a reflected wave from an object (for example, another vehicle or a two-wheeled vehicle) existing behind the vehicle A. This is a scanning millimeter wave radar that detects the distance between a rear object and the vehicle A. The radar 70 outputs a signal related to this detection distance to the ECU 18. The radar 70 is not limited to the millimeter wave radar, and various sensors such as a laser radar and an ultrasonic radar that can detect an object behind the vehicle can be employed.

  The collision sensor 71 is composed of an acceleration sensor that detects acceleration in the front-rear direction (including an oblique direction) of the vehicle A, and detects the collision of the vehicle A and also detects the collision acceleration and the direction at the time of the collision. And the signal regarding these detection information is output to ECU18.

  The occupant sensor 72 outputs a signal related to the presence or absence of an occupant in the passenger compartment of the vehicle A to the ECU 18.

  The parking switch 11 is a seesaw switch that can be turned on / off by the occupant. When the parking switch 11 is in the on state, the parking switch 11 continuously outputs an on signal to the ECU 18. On the other hand, the OFF signal is continuously output.

  The SCS controller 8 receives an input signal from the ECU 18 and executes SCS control in order to improve traveling stability when the vehicle A turns. Specifically, when the SCS controller 8 determines that the turning posture of the vehicle A has collapsed to a predetermined level or more based on detection signals from the lateral acceleration sensor 65, the wheel speed sensor 66, and the yaw rate sensor 63 input from the ECU 18. By controlling the operation of the pressurizing unit 7 (hydraulic pump 35 and each valve 32, 33) and controlling the braking force of each wheel 3, a yaw moment is applied around the center of gravity of the vehicle A. The turning posture of the vehicle A is converged toward the target direction.

  Further, the SCS controller 8 receives an input signal from the ECU 18 and executes ABS control in order to prevent the wheels 3 from being locked. Specifically, the SCS controller 8 calculates the slip rate of each wheel 3 based on the detection signal of the wheel speed sensor 66 input from the ECU 18, and selects the wheel 3 whose calculated slip rate exceeds a predetermined threshold value. When detected, the braking force acting on the wheel 3 is reduced by controlling the operation of the pressurizing unit 7 to prevent the wheel lock.

  The EPB controller 10 operates the electric motor 48 based on the on / off signal of the parking switch 11 and the braking control signal (first braking signal / second braking signal / braking stop signal) input from the ECU 18. By controlling the wheel braking force of the electric brake mechanism 9 (EPB device 15), 50% of the maximum braking force (hereinafter referred to as the first braking force) and 100% of the maximum braking force (hereinafter referred to as the second braking force). And 0 load (braking force = 0N).

  The EPB controller 10 normally controls the wheel braking force of the electric brake mechanism 9 based on this on / off signal except when the vehicle A collides with an object. That is, when the EPB controller 10 receives an off signal in a normal state, the wheel braking force of the electric brake mechanism 9 is set to zero load, and when the on signal is received, the wheel braking force is controlled to the first braking force. To do.

  Further, the EPB controller 10 controls the wheel braking force of the electric brake mechanism 9 based on a braking control signal input from the ECU 18 when the vehicle A collides with an object. Specifically, the EPB controller 10 controls the wheel braking force of the electric brake mechanism 9 to the first braking force when receiving the first braking signal from the ECU 18, and controls the wheel braking force when receiving the second braking signal. The power is controlled to the second braking force, and when the brake release signal is received, the operation of the electric motor 48 is controlled to control the wheel braking force to zero load.

  Based on the input signal from the radar 70, the ECU 18 determines whether or not the object exists within a predetermined range of the vehicle A and the rear of the vehicle. By calculating the time change of the distance, the relative speed of the object with respect to the vehicle A (equal to the absolute speed of the object when the vehicle A is stopped) is calculated. Then, the ECU 18 determines, based on the calculated relative speed and the distance of the object from the vehicle A, the collision time until the object collides with the vehicle A assuming that the relative speed is maintained. When it is determined that the following will occur, the object is predicted to collide with the vehicle A. This predetermined collision time is longer than the time required for the EPB device 15 to increase the wheel braking force from zero load to the second braking force upon receiving a control signal from the ECU 18 (hereinafter referred to as the maximum response time). It is preferable to set, for example, it may be set from 1 second to 2 seconds.

  The ECU 18 calculates a collision acceleration in the front-rear direction of the vehicle (hereinafter simply referred to as a collision acceleration) based on a signal from the collision sensor 71, and if the calculated collision acceleration is equal to or greater than the first threshold acceleration, the collision is detected. It is assumed that the collision is a heavy collision (a collision in which the collision acceleration of the vehicle A is equal to or higher than the second threshold acceleration (> first threshold acceleration)) or a light collision (the collision acceleration of the vehicle A is less than the second threshold acceleration). A collision).

  Then, when the vehicle A is stopped, the ECU 18 outputs a necessary control signal to the EPB controller 10 when predicting a collision with an object approaching the vehicle A from behind. Then, the braking force increase control for operating the EPB device 15 in the direction in which the wheel braking force increases is performed, and when it is determined that the object has collided with the vehicle A after the collision prediction, Impact level control is performed to control the operation of the EPB device 15 depending on whether the collision is a heavy collision or a light collision.

  Next, brake control (including braking force increase control and impact response control) of the EPB device 15 while the vehicle is stopped in the ECU 18 will be described with reference to the flowchart of FIG.

  In step S1, input signals from the sensors 62 to 72 and the switches 11 and 61 are read.

  In step S2, it is determined whether or not the object behind the vehicle is predicted to collide with the vehicle A based on the input signal from the radar 70. If YES, the process proceeds to step S4. If NO, the process proceeds to step S4. Proceed to S3.

  In step S3, based on the input signal from the collision sensor 71, it is determined whether or not there has been a collision. If this determination is NO, the process returns to step S2, while if YES, the process proceeds to step S4.

  In step S4, the wheel braking force of the EPB device 15 is increased by outputting the second braking signal to the EPB controller 10. In the state before the processing of step S4 is executed, the wheel braking force of the EPB device 15 is the first braking force if the parking switch 11 is in the on state, and the switch 11 is in the off state. If it is, the load is zero, so if the second braking signal is output to the EPB controller 10, the wheel braking force of the EPB device 15 starts to increase.

  In step S5, based on the input signal from the occupant sensor 72, it is determined whether or not there is an occupant in the passenger compartment of the vehicle A. If this determination is NO, the process returns. If YES, the process returns to step S6. move on.

  In step S6, based on the input signal from the steering angle sensor 64, it is determined whether or not the steering angle θp of the steering wheel 12 is a predetermined steering angle θs (for example, 5 ° to 7 ° or more), and this determination is NO. When the answer is YES, the process proceeds to step S7.

  In step S7, based on the input signal from the collision sensor 71, it is determined whether or not a collision has occurred. If this determination is NO, the process returns. If YES, the process proceeds to step S8. If it is determined that there is a collision once after executing the process in step S3, the process may proceed to step S8 without performing the process in step S7.

  In step S8, the collision acceleration at the time of collision is calculated based on the input signal from the collision sensor 71, and the collision (collision in step S3 or step S7) is a heavy collision based on the calculated collision acceleration. It is determined whether or not. If this determination is NO, the process returns. If YES, the process proceeds to step S9.

  In step S9, by outputting a first braking signal to the EPB controller 10, the wheel braking force of the EPB device 15 is reduced from the second braking force to the first braking force, and then the process returns.

  Therefore, for example, when the vehicle A is stopped with the parking switch 11 turned on, the ECU 18 predicts a collision between the vehicle A and an object approaching the vehicle A from behind. When the braking force increases, the braking force increase control is executed (the process of step S4 is executed), and the wheel braking force of the EPB device 15 starts to increase from the first braking force (see FIG. 5). Then, when the object collides with the vehicle A after the collision prediction, the wheel braking force of the EPB device 15 becomes higher than the first braking force (second braking force in FIG. 5).

  Thereby, the wheel braking force at the time of the collision can be sufficiently secured to prevent the secondary collision, and the initial impact acting on the occupant in the passenger compartment of the vehicle A can be reduced. Here, the ECU 18 predicts that the collision between the vehicle A and the object will occur when the time until the collision between the vehicle A and the object becomes equal to or shorter than the predetermined collision time. It is set longer than 15 maximum response times. For this reason, in most cases of a collision when the vehicle A is stopped, as shown in FIG. 5, the wheel braking force of the EPB device 15 is set to the maximum braking force between the time when the collision is predicted and the time when it actually collides. A second braking force can be increased, whereby a secondary collision can be reliably prevented and an initial impact acting on the occupant can be reduced.

  After the rear vehicle collides with the vehicle A, if the condition that the occupant is present in the vehicle compartment and the steering angle θp is equal to or smaller than the predetermined steering angle θs is established, the ECU 18 performs the impact degree control (step Steps S8 and S9) are executed. As a result, when the collision between the vehicle A and the object is a heavy collision, the wheel braking force of the EPB device 15 is reduced to the first braking force. On the other hand, when the collision is a light collision, the EPB device The wheel braking force of 15 is maintained as the second braking force.

  Thus, when the collision is a heavy collision, the wheel braking force is weakened, so that the rebound force (reaction force) acting on the passenger in the vehicle interior due to the impact can be reduced, and the passenger in the vehicle interior can be reliably Can be protected.

  Further, for example, when the vehicle A is stopped in a state where the occupant turns off the parking switch 11 (the wheel braking force of the EPB device 15 is 0 load), the vehicle is collided with an object behind the vehicle A. When the ECU 18 predicts a collision between the vehicle A and the rear vehicle, as shown in FIG. 6, the wheel braking force of the EPB device 15 starts to increase, and then the object collides with the vehicle A. If the collision is a heavy collision, the wheel braking force increases to the second braking force. If the collision is a light collision, the wheel braking force decreases to the first braking force. In this way, it is possible to obtain the same operational effects as the case described above (the case where the vehicle A is rear-crashed with the parking switch 11 turned on). Here, in the case shown in FIG. 6, since the time from the prediction of the collision in the ECU 18 to the actual collision is shorter than the maximum response time of the EPB device 15, the wheel braking force of the EPB device 15 at the time of the collision is the second braking force. It is lower than the power. Even in such a case, the wheel braking force at the time of the collision should be sufficiently high (higher than the first braking force in FIG. 6) as compared with the case where the EPB device 15 is operated after the collision occurs. Can do. Therefore, it is possible to reliably prevent a secondary collision due to a collision and sufficiently reduce the initial impact acting on the occupant.

  Here, the impact degree control by the ECU 18 is not executed when no occupant is present in the vehicle interior (when the determination in step S5 is NO), as shown in FIG.

  Therefore, it is possible to prevent the wheel braking force of the EPB device 15 from being unnecessarily reduced due to the impact level control being executed by the ECU 18 after the occurrence of the collision until there is no need for passenger protection. The secondary collision of the vehicle A can be prevented more reliably.

  Further, the impact degree control by the ECU 18 is not executed when the steering angle θp of the steering wheel 12 is larger than the predetermined steering angle (when the determination in step S6 is NO).

  Therefore, even if the steering angle θp of the steering wheel 12 is large, the impact response control is executed after the collision and the braking force is reduced, so that the vehicle A can surely spin or jump out to the oncoming lane. Can be prevented.

(Other embodiments)
The configuration of the present invention is not limited to the above embodiment, but includes various other configurations. That is, in the above embodiment, the object approaching from the rear of the vehicle is detected by the radar 70. However, the present invention is not limited to this, and the object approaching from the front of the vehicle by the radar 70 is detected. Alternatively, an object approaching from the side of the vehicle may be detected.

  In the above embodiment, the ECU 18 calculates the distance of the object from the vehicle A based on the input signal from the radar 70. For example, instead of the radar 70, an in-vehicle camera is provided, You may make it obtain | require the distance from this vehicle A of a target object by image-processing the picked-up image of this vehicle-mounted camera in ECU18.

  In the above embodiment, the collision prediction between the vehicle A and the object in the ECU 18 is performed based on the distance signal from the radar 70. However, the present invention is not limited to this. For example, the object communicates with the object. If the vehicle has a function, collision prediction may be performed by inter-vehicle communication.

  In the above embodiment, the collision acceleration of the vehicle A is detected by the collision sensor 71 when the collision occurs. However, the present invention is not limited to this. For example, the ECU 18 captures an image of an object captured by an in-vehicle camera. Based on the estimated information, the weight and speed of the vehicle A may be estimated, and the collision acceleration of the vehicle A at the time of the collision may be predicted before the collision occurs. If the vehicle has a vehicle, the weight and speed of the object are acquired by inter-vehicle communication, and based on this acquired information, the collision acceleration of the vehicle A when the collision occurs is predicted before the collision occurs. Good.

  In the above embodiment, the maximum braking force of the EPB device 15 is the second braking force. For example, the electric motor 48 has a limit current (a maximum value in a current region that is not normally used from the viewpoint of durability). The wheel braking force (greater than the maximum braking force) of the EPB device 15 obtained by flowing the flow may be used as the second braking force.

  The present invention relates to an actual collision detecting means for detecting a collision of a vehicle, an electric parking brake device for braking a wheel by driving an electric brake mechanism, and the electric parking brake based on collision detection information by the actual collision detecting means. The present invention is useful for a vehicle braking device including a control unit that controls the operating state of the device, and particularly useful for a vehicle including an acceleration sensor that detects a collision acceleration in the front-rear direction as an actual collision detection unit.

1 is a schematic plan view of a vehicle equipped with a vehicle braking device according to an embodiment of the present invention. It is sectional drawing which shows the pressurization unit which is a part of a foot brake device, an electric parking brake device, and an SCS device. It is a block diagram which shows the structure of a braking device. It is a flowchart which shows the brake control in ECU. When an object collides with a vehicle that is stopped with the parking switch turned on, the time of wheel braking force of the EPB device for each of the case where the collision is a heavy collision and the case of a light collision It is the graph which showed the mode of change. When an object collides with a stopped vehicle with the parking switch turned off, the time of the wheel braking force of the EPB device for each of the collision is a heavy collision and a light collision. It is the graph which showed the mode of change. When an object collides with a vehicle that is parked with the parking switch turned on, when the impact level control is executed and when it is not executed, It is the graph which showed the mode of the time change of the wheel braking force of an EPB apparatus.

A vehicle 3 wheel 9 electric brake mechanism 15 electric parking brake device 18 ECU (control means, collision prediction means, actual collision detection means, impact degree acquisition means,
(Steering angle detection means, occupant detection means)
64 Rudder angle sensor (steering angle detection means)
70 Radar (collision prediction means)
71 Collision sensor (actual collision detection means, impact level acquisition means)
72 Occupant sensor (Occupant detection means)

Claims (5)

Based on actual collision detection means for detecting a vehicle collision, an electric parking brake device for braking the wheels of the vehicle by operating an electric brake mechanism driven by an electric actuator, and collision detection information by the actual collision detection means. And a control means for controlling the operation of the electric parking brake device, and a vehicle braking device comprising:
A collision prediction means for detecting an object approaching the vehicle and detecting whether the object is predicted to collide with the vehicle;
A degree of impact acquisition means for acquiring a collision acceleration at the time of a collision with the object in the vehicle by prediction or detection;
When the vehicle is stopped, the control means moves the electric parking brake device in a direction in which the wheel braking force increases when the collision prediction means predicts a collision between the vehicle and the object. When a collision between the vehicle and the object is detected by the actual collision detection unit after the braking force increase control to be activated is performed and the collision prediction unit predicts a collision, the electric parking brake device after the detection is detected. Is configured to execute impact degree corresponding control for controlling the operation according to the magnitude of the collision acceleration at the time of the collision obtained by the impact degree obtaining unit ,
Further comprising a steering angle detection means for detecting the steering angle of the wheel,
Furthermore, the control means is configured to prohibit the execution of the impact degree corresponding control when the steering angle detected by the steering angle detection means is a predetermined angle or more . Based on actual collision detection means for detecting a vehicle collision, an electric parking brake device for braking the wheels of the vehicle by operating an electric brake mechanism driven by an electric actuator, and collision detection information by the actual collision detection means. And a control means for controlling the operation of the electric parking brake device, and a vehicle braking device comprising:
A collision prediction means for detecting an object approaching the vehicle and detecting whether the object is predicted to collide with the vehicle;
A degree of impact acquisition means for acquiring a collision acceleration at the time of a collision with the object in the vehicle by prediction or detection;
When the vehicle is stopped, the control means moves the electric parking brake device in a direction in which the wheel braking force increases when the collision prediction means predicts a collision between the vehicle and the object. When a collision between the vehicle and the object is detected by the actual collision detection unit after the braking force increase control to be activated is performed and the collision prediction unit predicts a collision, the electric parking brake device after the detection is detected. Is configured to execute impact degree corresponding control for controlling the operation according to the magnitude of the collision acceleration at the time of the collision obtained by the impact degree obtaining unit,
Occupant detection means for detecting whether there is an occupant in the vehicle compartment of the vehicle,
Furthermore, the control means is configured to prohibit the execution of the impact degree corresponding control when the presence of an occupant is not detected by the occupant detection means. The vehicle braking device according to claim 1 or 2 ,
In the impact degree corresponding control, when the impact acceleration acquired by the impact level acquisition unit is greater than or equal to a predetermined value, the wheel braking force of the electric parking brake device is reduced as compared with a case where the impact acceleration is less than the predetermined value. A braking device for a vehicle, which operates an electric parking brake device. The vehicle braking device according to claim 3 ,
The electric parking brake device is configured to be able to switch the wheel braking force between a first braking force and a second braking force larger than the first braking force,
When the impact acceleration acquired by the impact level acquisition means is greater than or equal to the predetermined value, the impact level control performs the wheel braking force of the electric parking brake device as the first braking force, When the acceleration is less than the predetermined value, the electric parking brake device is operated so that the wheel braking force of the electric parking brake device becomes the second braking force. . The vehicle braking device according to claim 4 ,
In the braking force increase control, when a collision between the vehicle and the object is predicted by the collision prediction means while the vehicle is stopped, the wheel braking of the electric parking brake device is released or the When the wheel braking force is the first braking force, the electric parking brake device is operated in a direction in which the wheel braking force of the electric parking brake device increases toward the second braking force. A vehicle braking device characterized by the above.

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