JP6680147B2 - Active device actuator - Google Patents

Description

  The present invention relates to an active device actuation device that actuates an active device for pedestrian protection.

  BACKGROUND ART Conventionally, active devices such as airbag devices that protect pedestrians when a vehicle and a pedestrian collide are known.

  For example, a deformation sensor is provided in a vehicle, and an active device such as an airbag device that protects a pedestrian is activated based on the strength of a load at the time of a collision and the relative speed between the vehicle and an object detected immediately before the collision. There is known a technique for determining (see Patent Document 1, for example). In this technology, the load applied to the front bumper at the time of a collision occurs is calculated from the output signal of the deformation sensor, and the calculated load and the temporal change of the strain energy generated by the deformation of the front bumper at the time of the collision are output from the deformation sensor. Based on this, the relative speed between the vehicle and the object is calculated. Then, it is determined whether or not the load and the relative speed exceed the threshold value, and the operation of the active device that protects the pedestrian is determined.

JP 2006-248508 A

  However, the output signal of the deformation sensor provided on the vehicle may be momentarily interrupted (temporarily interrupted). When the output signal of the deformation sensor is momentarily cut off, the load and the relative speed cannot be temporarily obtained, and the determination of the active device operation may become unstable. Therefore, there is room for improvement in operating the active device that protects a pedestrian based on the pressure detected by the pressure sensor with a simple configuration and simple processing.

  The present invention has been made in consideration of the above facts, and an object of the present invention is to provide an active device actuation device that can improve the actuation performance of an active device with a simple configuration and a simple process.

  In order to achieve the above object, the active device actuating device of the present invention includes a vehicle speed detection unit for detecting a vehicle speed of a vehicle, and a pressure generated by the vehicle bumper when an object collides with the vehicle bumper. In a state where the vehicle speed detected by the vehicle speed detection unit and the pressure detection unit that outputs a signal are within a predetermined range, and the level of the pressure signal output from the pressure detection unit is equal to or higher than the first threshold value for pedestrian detection. When the pressure detection unit is normal, the pedestrian protection active device is activated when the amount of change in the pressure signal is equal to or greater than a second threshold, and when the pressure detection unit is abnormal, an abnormality occurs. And a control unit that controls the operation of the active device for pedestrian protection when the occurrence of the above occurs.

  According to the present invention, the vehicle speed detector detects the vehicle speed of the vehicle, and the pressure detector detects the pressure generated in the vehicle bumper when the pedestrian collides with the vehicle bumper and outputs a pressure signal.

  By the way, when an object collides with a vehicle (for example, a vehicle bumper), the time change of the pressure generated in the vehicle bumper differs depending on the relative speed between the vehicle and the object. For example, in a collision between an object and a vehicle whose relative speed is smaller than that of a pedestrian, it takes time for the pressure to reach a peak, and it is not necessary to activate an active device that protects the pedestrian. It may be a collision.

  Therefore, the control unit determines that the vehicle speed detected by the vehicle speed detection unit is within a predetermined range defined as the vehicle speed at which the active device that protects the pedestrian is activated, and the pressure detected by the pressure detection unit is used for pedestrian detection. When the change amount of the pressure is equal to or more than the second threshold value in the state of the first threshold value or more, the control for operating the pedestrian protection active device is performed.

  In this way, the control for activating the active device is performed based on the vehicle speed, the pressure, and the pressure change amount corresponding to the relative speed at the time of a collision. This makes it possible to detect a collision with a pedestrian with higher accuracy and improve the collision detection performance. Therefore, the collision detection performance can be improved with a simple configuration and a simple process.

  However, an abnormality may occur in the pressure amount detection unit. For example, an abnormality may occur such that the pressure detection is momentarily interrupted, or the output signal of the signal indicating the pressure detected by the pressure detector is momentarily interrupted. Therefore, the control unit of the active device actuating device of the present invention, when the vehicle speed is within a predetermined range, the level of the pressure signal is equal to or higher than the first threshold value for pedestrian detection, and the pressure detection unit is normal, When the change amount of the pressure signal is equal to or more than the second threshold value, the pedestrian protection active device is activated, and when an abnormality of the pressure detection unit occurs, the pedestrian protection active device is activated when the abnormality occurs. Take control.

  In this way, when an abnormality such as an instantaneous interruption (instantaneous interruption) of the output of the pressure detection unit occurs, the active device is operated without considering the pressure change amount corresponding to the relative speed. This makes it possible to detect collisions with pedestrians with higher accuracy because the determination of active device operation does not become unstable even if an abnormality occurs in the pressure detection unit, improving collision detection performance. Can be made.

  As described above, according to the present invention, there is an effect that the operating performance of the active device can be improved with a simple configuration and a simple process.

It is a block diagram showing an example of a schematic structure of an active device operation device concerning this embodiment. It is an exploded perspective view showing a schematic structure around a vehicle bumper concerning this embodiment. It is a partially expanded sectional view showing a schematic structure around a bumper for vehicles concerning this embodiment. It is a diagram showing an example of the characteristic which shows the relation between the pressure which occurs in the bumper for vehicles when operating the active device concerning this embodiment, and vehicle speed. It is a diagram showing an example of a pressure characteristic generated at the time of a collision according to the present embodiment. It is a diagram showing an example of a pressure characteristic generated at the time of a collision according to the present embodiment. An example of the characteristic showing the pressure gradient with respect to the pressure characteristic according to the present embodiment is shown. It is a flow chart which shows an example of a flow of processing performed by a control device of an active device operation device concerning this embodiment. It is a block diagram which shows an example of the collision detection module which implement | achieves the active device actuator which concerns on this embodiment by hardware. It is a block diagram showing an example of a collision speed judgment part concerning this embodiment.

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

  FIG. 1 shows a schematic configuration of an active device operation device according to this embodiment. The active device operation device 10 includes a control device 12 that performs various controls for detecting a collision between a vehicle and an object.

  The control device 12 is composed of a microcomputer including a CPU 14, a ROM 16, a RAM 18, and an I / O 20. The CPU 14, the ROM 16, the RAM 18, and the I / O 20 are connected via a bus 21 so that commands and data can be exchanged. There is.

  The ROM 16 stores a program for detecting a collision between the vehicle and the object, a threshold value for detecting the collision, and the like, and the CPU 14 executes the program stored in the ROM 16 so that the vehicle and the object can be detected. Control is performed to detect a collision. The RAM 18 is used as a cache memory or the like when executing the program.

  A vehicle-mounted camera 22, a contact sensor 24, a vehicle speed sensor 26, and an active device 28 are connected to the I / O 20. The vehicle-mounted camera 22, the contact sensor 24, and the vehicle speed sensor 26 are detectors for detecting the state of the vehicle. The vehicle-mounted camera 22 is a non-contact detector that functions as a preventive sensor that detects an object in front of the vehicle that may collide with the vehicle by capturing an image of the front of the vehicle. Another example of a detector that functions as a preventive sensor is an on-vehicle radar that scans ahead of the vehicle. The contact sensor 24 is a detector that detects a physical quantity related to pressure generated by collision of an object at a predetermined position of the vehicle bumper (details will be described later). The contact sensor 24 detects the pressure f in the pressure chamber or the pressure tube by providing the pressure chamber, the pressure tube, or the like on the vehicle bumper. The vehicle speed sensor 26 is a detector that detects the speed of the vehicle (vehicle speed Va).

  The active device 28 is a device for activating a protection device for protecting a pedestrian when the object is a pedestrian when the vehicle collides with the object. As the active device 28, for example, a device such as a gas generator that operates a pop-up hood that raises the hood to absorb a shock to a pedestrian or an inflator that operates an airbag device that is deployed on the hood may be applied. it can.

  The control device 12 detects a collision between the vehicle and an object based on the detection values of the vehicle-mounted camera 22, the contact sensor 24, and the vehicle speed sensor 26, and activates the active device 28 when the object is a pedestrian. Control to do.

  In the present embodiment, the active device 28 is an example of the pedestrian protection active device of the present invention. The contact sensor 24 is an example of the pressure detection unit of the present invention, and the vehicle speed sensor 26 is an example of the vehicle speed detection unit of the present invention. The control device 12 is an example of the control unit of the present invention.

  FIG. 2 is an exploded perspective view showing a schematic configuration around the vehicle bumper. In FIG. 2, arrow UP, arrow FR, and arrow OUT indicate the vehicle up-down direction upper side, the vehicle front-rear direction front side, and the vehicle width direction outer side (left side).

  The vehicle bumper 30 is provided, for example, in a front portion of a vehicle such as a passenger car. The vehicle bumper 30 includes a front bumper cover 32, a bumper reinforcement 34, and an absorber 38. A contact sensor 24 including a pressure tube 46 and a pressure sensor 48 is arranged on the vehicle rear side of the absorber 38 (details will be described later).

  The front bumper cover 32 covers the bumper reinforcement 34 from the vehicle front side, and is attached to a vehicle body such as the bumper reinforcement 34. An opening 32 </ b> A for introducing air into a radiator 42 arranged on the vehicle rear side of the bumper reinforcement 34 is formed in a lower portion of the front bumper cover 32. The bumper reinforcement 34 is formed in a long shape extending in the vehicle width direction and is arranged in the vehicle. The absorber 38 is arranged with the vehicle width direction as the longitudinal direction. The absorber 38 is arranged on the vehicle rear side of the front bumper cover 32.

  The vehicle-mounted camera 22 functioning as a preventive sensor can be attached above the vehicle bumper 30, for example, at a position such as a stay of a rear view mirror inside the vehicle. The active device actuating device 10 according to the present embodiment does not require to include the preventive sensor. The preventive sensor is a detector for detecting an object having a possibility of colliding with the vehicle (for example, an object in front of the vehicle). For example, from the image captured by the vehicle-mounted camera 22, it is possible to determine the type of the object in front of the vehicle, which may collide with the vehicle, including pedestrians. By providing the vehicle-mounted camera 22, it is possible to highly accurately determine that the object in front of the vehicle that may collide with the vehicle is a pedestrian.

  FIG. 3 shows a partially enlarged cross section of a schematic configuration around the vehicle bumper. The bumper reinforcement 34 is formed in a hollow, substantially rectangular columnar shape made of a metal material such as aluminum and is arranged on the vehicle rear side of the front bumper cover 32 with the vehicle width direction as the longitudinal direction.

  The absorber 38 is made of a foamed resin material, that is, urethane foam or the like, is provided between the front bumper cover 32 and the bumper reinforcement 34, and is formed in an elongated shape with the vehicle width direction as a longitudinal direction. . Further, the absorber 38 is formed in a substantially rectangular shape in a cross-sectional view as seen in the longitudinal direction. Further, the absorber 38 is disposed adjacent to a vehicle front side of a predetermined portion (for example, an upper portion) of the bumper reinforcement 34 and is fixed to a front surface 34A of the bumper reinforcement 34. Further, a holding groove portion 44 for holding a pressure tube 46 described later is formed on the rear surface 38A of the absorber 38. The holding groove portion 44 is formed in a substantially C-shape (specifically, a circular shape partially open to the rear side of the vehicle) opened to the rear side of the vehicle in a side sectional view, and penetrates in the longitudinal direction of the absorber 38. ing.

  The pressure tube 46 is connected to pressure sensors 48 provided at both ends in the vehicle width direction (see FIG. 2), and the pressure tube 46 and the pressure tube 46 constitute the contact sensor 24. That is, the contact sensor 24 is configured to include a pressure tube 46 formed in an elongated shape and a pressure sensor 48 that outputs a signal according to a pressure change of the pressure tube 46. Further, the pressure tube 46 is configured as a hollow structure having a substantially annular cross section. The outer diameter of the pressure tube 46 is set to be slightly smaller than the inner diameter of the holding groove portion 44 of the absorber 38, and the length of the pressure tube 46 in the longitudinal direction is equal to the length of the absorber 38 in the longitudinal direction. It is set longer than that. By assembling (fitting) the pressure tube 46 in the holding groove portion 44, the pressure tube 46 is arranged along the longitudinal direction of the absorber 38.

  In the state where the pressure tube 46 is assembled in the holding groove portion 44 of the absorber 38, the outer peripheral surface of the pressure tube 46 is in contact with the rear surface 50A of the absorber 38 or has a slight gap in a cross-sectional view seen from the longitudinal direction of the absorber 38. Will be placed. As a result, the pressure tube 46 is arranged adjacent to the front surface 34A of the bumper reinforcement 34, and when the load on the vehicle rear side acts on the absorber 38 and the absorber 38 presses the pressure tube 46, the bumper reinforcement 43 is pressed. A reaction force is generated on the pressure tube 46 by 34. The pressure sensors 48 provided at both ends of the pressure tube 46 in the vehicle width direction are electrically connected to the control device 12, and the pressure tube 46 is deformed, so that a signal corresponding to the pressure f in the pressure tube 46 is a pressure sensor. The data is output from the control device 48 to the control device 12.

  Although FIG. 2 shows an example in which the pressure sensors 48 are provided at both ends of the pressure tube 46, the pressure sensors 48 are not limited to being provided at both ends of the pressure tube 46. For example, it may be provided at any one end of the pressure tube 46, may be provided at the middle part of the pressure tube 46, or three or more of them may be provided in combination. Further, a plurality of contact sensors 24 configured by the pressure tube 46 and the pressure sensor 48 may be arranged in the vertical direction of the vehicle bumper 30.

  Next, the threshold value related to the collision between the vehicle and the object will be described.

  When a pedestrian collides with the vehicle bumper 30, the vehicle bumper 30 is deformed and a predetermined pressure f is generated on the vehicle bumper 30. Therefore, the pressure f when a pedestrian collides with the vehicle bumper 30 is obtained in advance, and is set as the first threshold th1 as a threshold for detecting the collision between the vehicle and the object. Accordingly, when the pressure f generated in the vehicle bumper 30 is equal to or higher than the first threshold value th1, it is possible to determine that the vehicle has collided with the pedestrian and activate the active device 28 that protects the pedestrian.

  When a pedestrian is protected by operating the active device 28 at the time of a collision between a vehicle and a pedestrian, since the walking speed of the pedestrian is lower than the vehicle speed Va, the vehicle speed Va should be approximately used as the speed at the time of the collision. it can. Further, there is a vehicle speed Va suitable for protecting a pedestrian by the operation of the active device 28 when a vehicle and a pedestrian collide. In other words, when protecting a pedestrian in front of a vehicle such as a hood, it is considered that the collision is mild when the vehicle is stopped or the vehicle speed Va is low, and the protective effect may be low even if the active device 28 is operated. Further, when the vehicle speed Va is high, the pedestrian may jump over the hood even if the active device 28 is operated, and the protective effect may be low. Therefore, in the present embodiment, as an example, the active device 28 is operated with a vehicle speed Va within a predetermined range (for example, 25 to 55 [km / h]) from a predetermined low speed V1 to a predetermined high speed V2. Determine the speed range to be used. The speed range in which the active device 28 is operated is an example, and may be determined according to the function of protecting the pedestrian by the active device 28.

  FIG. 4 shows the relationship between the pressure generated in the vehicle bumper 30 and the vehicle speed Va when the active device 28 is operated. In FIG. 4, an area AR showing a state at the time of collision in which the active device 28 can be operated is shown. That is, the state at the time of collision is included in the area AR in which the pressure f generated in the vehicle bumper 30 is equal to or higher than the first threshold value th1 and the vehicle speed Va is the range (speed range) of the vehicle speed Va from the low speed V1 to the high speed V2. If so, the active device 28 that protects the pedestrian can be activated.

  However, even if the object is other than a pedestrian in the state at the time of a collision in which the pressure f generated in the vehicle bumper 30 is equal to or higher than the first threshold th1 and the vehicle speed Va is included in the low speed V1 to the high speed V2 (area AR). The active device 28 is activated. Therefore, in the present embodiment, a physical quantity corresponding to the relative speed between the vehicle and the object is used for the collision determination in order to activate the active device 28 when the vehicle and the pedestrian collide.

  FIG. 5 shows an example of pressure characteristics in the case where objects having different relative speeds collide with the vehicle. When a vehicle and a pedestrian collide, the relative speed between the vehicle and the object can be approximated to the vehicle speed Va, and the pressure characteristic indicated by the characteristic curve 50 that reaches the peak (time t1) of the pressure f in a relatively short time. Becomes On the other hand, when an object having a relative velocity smaller than that of a pedestrian collides with the vehicle, a peak of the pressure f (time t2) elapses longer than a peak of the pressure f (time t1) at the time of collision with the pedestrian. The pressure characteristic shown by the characteristic curve 51 is reached. As shown in FIG. 5, the pressure characteristic indicated by the characteristic curve 50 and the pressure characteristic indicated by the characteristic curve 51 differ in the pressure gradient k (the amount of change in the pressure f per unit time). In the example shown in FIG. 5, the pressure gradient k of the pressure characteristic at the time of the collision with the object having a small relative velocity is smaller than the pressure gradient k of the pressure characteristic at the time of the collision with the pedestrian.

  In the present embodiment, the active device 28 that protects the pedestrian is activated when the vehicle collides with the object with the pressure characteristic indicated by the characteristic curve 50 that is considered to be the pedestrian. On the other hand, when the relative velocity between the vehicle and the object collides with the object with the pressure characteristic shown by the characteristic curve 51 smaller than that when the object is a pedestrian, the active device 28 for protecting the pedestrian is used. Do not activate.

  In detail, the change characteristic of the pressure f generated in the vehicle bumper 30 at the time of the collision between the vehicle and the object corresponds to the relative speed between the vehicle and the object. The pressure f generated in the vehicle bumper 30 is proportional to the amount of intrusion of the object into the vehicle bumper 30. When the object collides with the vehicle at a relative speed smaller than the vehicle speed Va, it takes a long time to reach a certain amount of the object entering the vehicle bumper 30 as compared with the collision with the pedestrian. become. Therefore, the amount of intrusion of the object into the vehicle bumper 30 per unit time becomes smaller as the relative speed becomes smaller, and the relative speed corresponds to the time derivative of the amount of intrusion of the object. Further, the time derivative of the intrusion amount of the target object is proportional to the pressure gradient k (the amount of change in the pressure f per unit time) that shows the tendency in the time characteristic (pressure characteristic) regarding the pressure f generated in the vehicle bumper 30. Therefore, in this embodiment, the pressure gradient k is used for collision determination as a physical quantity corresponding to the relative speed between the vehicle and the object.

  FIG. 6 shows an example of pressure characteristics when an object having a different relative speed collides with the vehicle, and FIG. 7 shows an example of characteristics showing the pressure gradient k with respect to the pressure characteristics. In FIG. 6, the pressure characteristic (characteristic curve 52) when the vehicle and the pedestrian collide is shown by a solid line, and the pressure characteristic (characteristic curve 53 when the object collides with the vehicle at a relative speed smaller than that of the pedestrian). ) Is indicated by a dotted line. Further, in FIG. 7, a characteristic curve 54 showing the pressure gradient k in the pressure characteristic (characteristic curve 52) shown in FIG. 6 is shown by a solid line, and a characteristic curve showing the pressure gradient k in the pressure characteristic (characteristic curve 53) shown in FIG. 55 is indicated by a dotted line.

  As shown in FIG. 6, when objects having different relative velocities collide with the vehicle, the pressure f generated in the vehicle bumper 30 becomes equal to or higher than the first threshold th1 due to the respective pressure characteristics, and only the pressure determination determines both. For active device 28. On the other hand, as shown in FIG. 7, a characteristic showing a pressure gradient k with respect to a pressure characteristic (characteristic curve 50) at the time of collision with a pedestrian and a pressure characteristic at the time of collision with an object (other than a pedestrian) having a small relative speed. The maximum value of the pressure gradient k is different from the characteristic indicating the pressure gradient k with respect to the (characteristic curve 51). In the example shown in FIG. 5, the pressure gradient k of the pressure characteristic at the time of the collision with the object having a small relative velocity is smaller than the pressure gradient k of the pressure characteristic at the time of the collision with the pedestrian. Therefore, the value of the pressure gradient k capable of discriminating the pressure gradient k at the time of collision with a pedestrian and the pressure gradient k at the time of collision with an object (other than a pedestrian) having a small relative speed is set as the second threshold value th2. . By setting the second threshold value related to the pressure gradient k, the value indicated by the pressure gradient k becomes equal to or larger than the second threshold value th2 at the time of collision with a pedestrian, and the value indicated by the pressure gradient k becomes at the time of collision with an object having a small relative speed. , The second threshold th2 is not reached. In this way, pedestrians can be identified.

  Thus, in order to operate the active device 28 at the time of a collision between the vehicle and a pedestrian, the physical quantity corresponding to the relative speed between the vehicle and the object is used for the collision determination. That is, in the present embodiment, the pressure gradient k of the pressure f generated in the vehicle bumper 30 in the case of a collision with a pedestrian is obtained in advance and the second threshold value is used as a threshold for detecting the collision between the vehicle and the pedestrian. The threshold th2 is set. Accordingly, when the pressure gradient k is equal to or larger than the second threshold value th2, it is possible to detect that the vehicle has collided with the pedestrian.

  By the way, when the pressure gradient k of the pressure f generated in the vehicle bumper 30 is used to detect a collision with a pedestrian, it is required that the contact sensor 24 always output an output signal. However, when the output signal of the contact sensor 24 is momentarily interrupted (temporary interruption), for example, the sensor output of the pressure sensor 48 is momentarily interrupted, or the output signal indicating the pressure f detected by the pressure sensor 48 is momentarily interrupted. When an abnormality such as being caused occurs, the pressure gradient k of the pressure f generated in the vehicle bumper 30 cannot be obtained, and the collision determination between the vehicle and the object becomes unstable.

  Therefore, in this embodiment, for example, an abnormality such as a momentary interruption of the sensor output of the pressure sensor 48 or a momentary interruption of the output signal indicating the pressure f detected by the pressure sensor 48 is detected. When an abnormality is detected, it is determined that the pressure gradient k is equal to or larger than the second threshold value th2 and the active device is activated. That is, when an abnormality such as a situation where the signal for obtaining the pressure gradient k is momentarily cut off is detected, the pressure generated in the vehicle bumper 30 used as a physical quantity corresponding to the relative speed between the vehicle and the object. The determination based on the pressure gradient k of f is determined as a collision with a pedestrian. In other words, the collision determination is performed without considering the determination based on the relative speed using the pressure gradient k. As a result, the collision determination between the vehicle and the object is not unstable, and the collision determination can be performed based on the pressure f generated in the vehicle bumper 30 and the vehicle speed Va in a state other than the momentary disconnection state, The active device 28 that protects a pedestrian with high accuracy can be activated.

Next, an example of processing executed by the control device 12 of the active device actuation device 10 according to the present embodiment will be described.
FIG. 8 shows an example of the flow of processing executed by the control device 12 of the active device operation device 10 according to this embodiment. In the present embodiment, the control device 12 executes the program stored in the ROM 16 in advance, which embodies an example of the processing flow shown in FIG. 8. The process of FIG. 8 is started when an ignition switch (not shown) is turned on.

  First, when the ignition switch is turned on, the process proceeds to step S100, and the vehicle speed Va is detected by reading the output signal of the vehicle speed sensor 26. In the next step S102, the collision state is detected based on the output signal of the contact sensor 24. Specifically, the controller 12 detects the pressure f generated in the vehicle bumper 30 by reading the output value of the contact sensor 24.

  Next, in step S104, it is determined whether the vehicle speed Va is within a predetermined range (V2 ≧ Va ≧ V1). As described above, the predetermined range is a predetermined range of the vehicle speed Va suitable for protecting the pedestrian by the operation of the active device 28. When a negative determination is made in step 104 (V1> Va, Va> V2), the process proceeds to step S116. In step S116, the process proceeds to step S118 without instructing to operate the active device 28. That is, the control device 12 proceeds with the process without outputting an operation signal indicating an instruction to operate the active device 28.

  On the other hand, if an affirmative decision is made in step S104 (V2 ≧ Va ≧ V1), the operation proceeds to step S106. In step S106, it is determined whether the pressure f is equal to or higher than the first threshold value (f ≧ th1). As described above, the first threshold th1 is a predetermined pressure f that is generated in the vehicle bumper 30 when a pedestrian collides with the vehicle bumper 30. If the affirmative judgment is made in step S106 (f ≧ th1), the routine proceeds to step S108, and if the negative judgment is made (f <th1), the routine proceeds to step S116.

  In step S108, it is determined whether the contact sensor 28 has "no abnormality". That is, for example, the control device 12 monitors the output signal of the contact sensor 28 (pressure sensor 48), determines that there is no abnormality when the output signal is always output from the contact sensor 28, and the pressure sensor 48 is detected. It is determined that there is an abnormality such as a momentary interruption of the sensor output or a momentary interruption of the output signal indicating the pressure f detected by the pressure sensor 48.

  When a positive determination is made in step S108 (no abnormality), the pressure gradient k of the pressure f is derived in step S110, and the process proceeds to step S112. In step S112, it is determined whether the pressure gradient k is greater than or equal to the second threshold (k ≧ th2). As described above, the second threshold value th2 is a pressure gradient k capable of discriminating the pressure gradient k at the time of a collision with a pedestrian and the pressure gradient k at the time of a collision with an object (other than a pedestrian) having a small relative speed. Is set in advance as the second threshold th2. When a negative determination is made in step S112 (k <th2), the process proceeds to step S116.

  If an affirmative decision is made in step S112 (k ≧ th2), the operation proceeds to step S114, and an operation instruction for the active device 28 is issued. That is, the controller 12 outputs an activation signal indicating an instruction to activate the active device 28. This activates the active device 28 to protect the pedestrian. After the operation signal is output in step S114, the process proceeds to step 118. In step 118, it is determined whether or not the process is terminated by determining that the ignition switch is turned off. If the determination is affirmative, the process routine is terminated, and if the determination is negative, step 100 Return processing to.

  On the other hand, if a negative determination is made in step S108 (there is an abnormality), the process proceeds to step S114. That is, when an abnormality is detected in the contact sensor 28 (pressure sensor 48), the active device is operated in step S114 without deriving and determining the pressure gradient k. When the abnormality is detected in the contact sensor 28 (pressure sensor 48), the process shifts to step S114, and the pressure gradient k is equal to or more than the second threshold th2, and the active device is activated. That is, when an abnormality such as a situation where the signal for obtaining the pressure gradient k is momentarily cut off is detected, the determination of the pressure f based on the pressure gradient k is performed as if it is a collision with a pedestrian. Equivalent to. As a result, the active device 28 that protects a pedestrian can be operated with high accuracy without making the collision determination between the vehicle and the object unstable.

  If it is not necessary to continuously execute this processing routine after outputting the operation signal to the active device 28, this processing routine may be ended after the processing of step 114.

  In the present embodiment, the processing performed by executing the program showing the processing flow shown in FIG. 5 has been described, but the processing of the program may be realized by hardware.

  FIG. 9 shows an example of the collision detection module 13 as hardware that detects a collision between a vehicle and an object and operates the active device 28.

  As shown in FIG. 9, the collision detection module 13 includes a vehicle speed determination unit 60, a collision pressure determination unit 62, a collision speed determination unit 64, and an AND element 66. The output signal of the vehicle speed sensor 26 (vehicle speed Va) and the output signal of the contact sensor 24 (pressure f) are input to the collision detection module 13. The collision detection module 13 also outputs an actuation signal to the active device 28.

  The output signal (pressure f) of the contact sensor 24 is input from each of the pressure sensors 48 provided at both ends of the pressure tube 46, but in FIG. The case where each is collectively input is shown. In addition, a signal indicating an abnormality of the contact sensor 28 (pressure sensor 48) is input to the collision detection module 13. In the present embodiment, since the collision speed determination unit 64, which will be described in detail later, detects an abnormality, it is not required to input a signal indicating the abnormality from the outside of the collision detection module 13. However, if a device for detecting an abnormality in the contact sensor 28 (pressure sensor 48) is separately provided, a signal indicating the abnormality may be input from the outside of the collision detection module 13.

  The vehicle speed determination unit 60 is a functional unit that determines that the vehicle speed Va at the time of a collision is a vehicle speed Va suitable for protecting a pedestrian by operating the active device 28. For example, the vehicle speed determination unit 60 has a predetermined range of the vehicle speed Va at which the operation of the active device 28 is suppressed while the vehicle is stopped or the vehicle is traveling. The predetermined range of the vehicle speed Va may be a speed range in which the active device 28 operates. The vehicle speed determination unit 60 compares the predetermined range of the vehicle speed Va determined in advance with the vehicle speed Va detected by the vehicle speed sensor 26, and outputs a high level signal when the vehicle speed Va is suitable for operating the active device 28. Output.

  The collision pressure determination unit 62 is a functional unit that determines from the output signal of the contact sensor 24 that the pressure f generated in the vehicle bumper 30 during a collision corresponds to a predetermined pressure f generated when a pedestrian collides. is there. The collision pressure determination unit 62 includes a first threshold value signal output unit that outputs a signal corresponding to the first threshold value th1 for detecting a pedestrian, and is high when the pressure f detected by the contact sensor 24 is equal to or higher than the first threshold value th1. Output level signal.

  The collision speed determination unit 64 determines that the pressure gradient k of the pressure f (a physical quantity corresponding to the relative speed between the vehicle and the object) derived from the time-series output signal of the contact sensor 24 is the pressure at the time of the collision between the vehicle and the pedestrian. It is a functional unit that determines that it corresponds to the gradient k (details will be described later). The collision speed determination unit 64 includes a second threshold value signal output unit that outputs a signal corresponding to the second threshold value th2 for pedestrian detection, and the pressure gradient k of the pressure f derived by the contact sensor 24 is equal to or greater than the second threshold value th2. In the case of, a high level signal is output.

  The AND element 66 outputs a logical product (AND) of the outputs of the vehicle speed determination unit 60, the collision pressure determination unit 62, and the collision speed determination unit 64. That is, when each of the vehicle speed determination unit 60, the collision pressure determination unit 62, and the collision speed determination unit 64 outputs a high level signal, the high level signal is an operation signal indicating an instruction to operate the active device 28. Output as.

  In this way, when the vehicle and the object collide, the output signal (pressure f) of the contact sensor 24 is the pressure f corresponding to the collision with the pedestrian, and the pedestrian is protected by the operation of the active device 28. When the vehicle speed is appropriate Va and the pressure gradient k corresponding to the relative speed is the relative speed corresponding to the collision between the vehicle and the pedestrian, the active device 28 is output as an operation signal indicating an operation instruction. As a result, compared with the case where the active device 28 is operated by determining the collision with the pedestrian by the determination based on the vehicle speed Va at the time of the collision and the determination based on the pressure f at the time of the collision, the active configuration is simple with the pressure gradient k derived. The operating performance of the device can be improved. Moreover, since the pressure gradient k can be derived from the change in the pressure f, the operating performance of the active device can be improved by a simple process.

  FIG. 10 shows a functional unit that determines a collision with a pedestrian based on the pressure gradient k as an example of the collision speed determination unit 64 that constitutes a part of the collision detection module 13. In FIG. 10, the signals input from the pressure sensors 48 provided at both ends of the pressure tube 46 are shown as the pressure sensor (R) and the pressure sensor (L). Further, corresponding to the pressure sensors 48 provided at both ends of the pressure tube 46, each of the signals indicating an abnormality that can be input is also shown as a sensor abnormality (R) and a sensor abnormality (L).

  As shown in FIG. 10, the collision speed determination unit 64 includes a preprocessing unit 70, a slope determination unit 72 to which a threshold value setting unit 73 that sets the second threshold value th2 is connected, abnormality detection units 74 and 75, an OR element 76, and The OR element 78 is provided. The collision speed determination unit 64 includes a pressure sensor (R) and a pressure sensor (R) indicating a signal input from each of the pressure sensors 48 provided at both ends of the pressure tube 46 as an output signal (pressure f) of the contact sensor 24. L) is input. Moreover, the collision speed determination unit 64 outputs a gradient determination signal. In addition, the sensor abnormality (R) and the sensor abnormality (L) indicating a signal indicating an inputable abnormality can be input corresponding to the pressure sensors 48 provided at both ends of the pressure tube 46.

  The pre-processing unit 70 is a functional unit that clears the phase difference by, for example, averaging the output signal of the contact sensor 24, that is, the signal input from each of the pressure sensors 48 provided at both ends of the pressure tube 46. Therefore, the preprocessing unit 70 combines the input pressure sensor (R) and pressure sensor (L) and outputs the combined signal as the output signal (pressure f) of the contact sensor 24.

  The gradient determination unit 72 is a functional unit that determines that the pressure gradient k of the pressure f generated in the vehicle bumper 30 during a collision corresponds to a predetermined pressure gradient k when a pedestrian collides. The slope determination unit 72 is connected to the threshold value setting unit 73 as a second threshold value signal output unit that outputs a signal corresponding to the second threshold value th2 for pedestrian detection, and the output of the contact sensor 24 input from the preprocessing unit 70. A pressure gradient k of the pressure f is derived based on the signal (pressure f), and a high level signal is output when the derived pressure gradient k is equal to or greater than the second threshold th2.

  The abnormality detection units 74 and 75 monitor the output signal of the contact sensor 28 (pressure sensor 48), and when the sensor output of the pressure sensor 48 is interrupted or the like, it is detected as a sensor abnormality and a high level is detected. Output a signal. When the contact sensor 28 constantly outputs an output signal, the abnormality detection units 74 and 75 output a low level signal.

  The OR element 76 outputs a logical sum (OR) of the outputs of the abnormality detection units 74 and 75 to the OR element 78. Therefore, when at least one sensor output of the pressure sensor 48 is momentarily cut off, a sensor abnormality is detected, and a high level signal is output to the OR element 78.

  Then, the OR element 78 outputs the logical sum (OR) of the output of the gradient determining unit 72 and the output of the OR element 76 as the gradient determining signal. Therefore, when at least one sensor output of the pressure sensor 48 is momentarily cut off, a sensor abnormality is detected, and a high level signal is output to the OR element 78.

  Therefore, the collision speed determination unit 64 outputs an operation signal indicating an instruction to operate the active device 28 when the pressure gradient k corresponding to the relative speed is the relative speed corresponding to the collision between the vehicle and the pedestrian. Output a high-level gradient determination signal for Further, the collision speed determination unit 64 is an operation signal indicating an instruction to operate the active device 28 when an abnormality such as an instantaneous interruption (instantaneous interruption) of the output of the contact sensor 28 (pressure sensor 48) occurs. And outputs a high-level gradient determination signal for outputting. As a result, even when the contact sensor 28 (pressure sensor 48) has an abnormality, the determination of the active device operation does not become unstable, so that a collision with a pedestrian can be detected with higher accuracy. The collision detection performance can be improved.

  As described above, in the present embodiment, when the vehicle collides with the object, the pressure f detected by the contact sensor 24 is the pressure f corresponding to the collision with the pedestrian, and the vehicle speed Va of the active device 28. When the vehicle speed Va is suitable for protecting a pedestrian by operation, and the pressure gradient k corresponding to the relative speed is the relative speed corresponding to the collision between the vehicle and the pedestrian, the active device 28 is operated. It is output as an operation signal indicating an instruction. As a result, compared with the case where the active device 28 is operated by determining the collision with the pedestrian by the determination based on the vehicle speed Va at the time of the collision and the determination based on the pressure f at the time of the collision, the active configuration is simple with the pressure gradient k derived. The operating performance of the device can be improved. Moreover, since the pressure gradient k can be derived from the change in the pressure f, the operating performance of the active device can be improved by a simple process.

  Further, in the present embodiment, when an abnormality such as a momentary interruption (temporary interruption) of the output of the contact sensor 28 (pressure sensor 48) occurs, an operation signal indicating an instruction to operate the active device 28 is output. And outputs a gradient determination signal to do so. As a result, even when the contact sensor 28 (pressure sensor 48) has an abnormality, the determination of the active device operation does not become unstable, so that a collision with a pedestrian can be detected with higher accuracy. The collision detection performance can be improved.

  Although the case where the pressure generated in the vehicle bumper is used has been described in the present embodiment, the effective mass calculated by the deformation amount at the time of the collision between the vehicle and the object may be used instead of the pressure.

  Further, in the present embodiment, the case where the pressure sensor is provided in the vehicle bumper 30 and the pressure generated in the vehicle bumper is used has been described. However, for example, a pressure chamber may be provided in the vehicle bumper 30 to detect the pressure. Good.

  Further, although the case where the pressure sensor is provided in the vehicle bumper 30 has been described in the present embodiment, for example, the pressure may be estimated by detecting the deformation amount of the vehicle bumper 30 using an acceleration sensor.

  Furthermore, although the present embodiment has been described by taking the front side of the vehicle as an example, the present invention may be applied to the vehicle periphery such as the rear side of the vehicle.

  Further, the processing performed by the control device 12 in the present embodiment may be stored in a storage medium or the like as a program and distributed.

Regarding the above embodiment, the following supplementary notes will be disclosed.
(Note 1)
A vehicle speed detection unit for detecting the vehicle speed of the vehicle,
A pressure detection unit that detects a pressure generated in the vehicle bumper when an object collides with the vehicle bumper and outputs a pressure signal,
When the vehicle speed detected by the vehicle speed detection unit is within a predetermined range, the level of the pressure signal output from the pressure detection unit is equal to or higher than the first threshold value for pedestrian detection, and the pressure detection unit is normal. When the amount of change in the pressure signal is equal to or more than a second threshold value, the pedestrian protection active device is activated, and when an abnormality occurs in the pressure detection unit, the pedestrian protection is performed at the time when the abnormality occurs. A control unit that controls the operation of the active device for
Active device actuating device with.
(Note 2)
The active device actuating device according to Note 1, wherein the abnormality of the pressure detection unit is a state of instantaneous interruption of the pressure signal.
(Note 3)
The active device according to Note 1 or 2, wherein the control unit includes a pressure change amount derivation unit that derives a change amount of pressure generated in the vehicle bumper based on a pressure signal output from the pressure detection unit. Actuator.
(Note 4)
The pressure detection unit includes a plurality of pressure sensors provided at different positions in the width direction of the vehicle, and detects the pressure generated in the vehicle bumper by the plurality of pressure sensors provided. The active device actuation device according to.
(Note 5)
The pressure change amount derivation unit derives, as the amount of change in pressure, a pressure gradient indicating a temporal change in pressure generated in the vehicle bumper, based on the pressure signal output from the pressure detection unit. 4. The active device actuation device according to any one of 4.
(Note 6)
The control unit determines a vehicle speed determination unit that determines whether the vehicle speed detected by the vehicle speed detection unit is within a predetermined range, and determines whether the pressure detected by the pressure detection unit is greater than or equal to a first threshold value for pedestrian detection. The operation determination unit includes a pressure determination unit, determination results of the vehicle speed determination unit and the pressure determination unit, and an operation determination unit that determines the operation of the pedestrian protection active device based on the amount of change in the pressure signal. Based on the determination result of the unit, a control unit that performs control to operate the pedestrian protection active device,
The vehicle speed determination unit determines that the vehicle speed detected by the vehicle speed detection unit is within a predetermined range, and the pressure determination unit outputs a pressure signal having a level equal to or higher than a first threshold value for pedestrian detection. In a state where it is determined that, when the pressure detection unit is normal, the operation determination unit performs a determination to operate the pedestrian protection active device when the change amount of the pressure signal is equal to or more than a second threshold value, The abnormal device of the said pressure detection part WHEREIN: The active device actuation apparatus as described in any one of the remarks 1 to 5 which performs determination which operates the said active device for pedestrian protection at the time of the abnormal condition.

10 Active Device Actuator 12 Control Device (Control Unit, Pressure Change Amount Derivation Unit)
13 Collision detection module (control unit, pressure change amount derivation unit)
24 Contact sensor (pressure detector)
26 Vehicle speed sensor (vehicle speed detector)
30 vehicle bumper 46 pressure tube 48 pressure sensor 60 vehicle speed determination unit 62 collision pressure determination unit 64 collision speed determination unit 72 gradient determination unit (pressure change amount derivation unit)
74 anomaly detector 75 anomaly detector th1 first threshold th2 second threshold

Claims (1)

A vehicle speed detection unit for detecting the vehicle speed of the vehicle,
A pressure detection unit that detects a pressure generated in the vehicle bumper when an object collides with the vehicle bumper and outputs a pressure signal,
When the vehicle speed detected by the vehicle speed detection unit is within a predetermined range, the level of the pressure signal output from the pressure detection unit is equal to or higher than the first threshold value for pedestrian detection, and the pressure detection unit is normal. When the amount of change in the pressure signal is equal to or more than a second threshold value, the pedestrian protection active device is activated, and when an abnormality occurs in the pressure detection unit, the pedestrian protection is performed at the time when the abnormality occurs. A control unit that controls the operation of the active device for
Active device actuating device with.