JP4678014B2 - Pedestrian collision detection device - Google Patents

Description

  The present invention relates to a pedestrian collision detection device that detects a collision with a pedestrian in a vehicle.

Conventionally, as a pedestrian collision detection device that detects a collision with a pedestrian in a vehicle, for example, there is an obstacle determination device for a vehicle disclosed in Japanese Patent Application Laid-Open No. 2006-117157. The vehicle obstacle determination device includes a pressure sensor, a vehicle speed sensor, and an airbag ECU device. The pressure sensor is installed in an absorber constituting the vehicle bumper and detects a pressure in a chamber formed in the absorber. The vehicle speed sensor is disposed in the vehicle and detects the traveling speed of the vehicle. The pressure sensor and the vehicle speed sensor are connected to the airbag ECU. The airbag ECU determines whether the obstacle colliding with the vehicle bumper is a pedestrian based on the detection results of the pressure sensor and the vehicle speed sensor. Specifically, the determination is made based on whether or not the pressure in the chamber exceeds a threshold value determined according to the traveling speed of the vehicle.
JP 2006-117157 A

  In the vehicle obstacle determination device described above, when an obstacle collides with the vehicle bumper, the vehicle bumper is deformed and the pressure in the chamber rises. When the obstacle is hard, the obstacle itself is not deformed. However, when the obstacle is soft, not only the vehicle bumper but also the obstacle is deformed. Therefore, even if the same kind of obstacle collides, the deformation of the vehicle bumper varies depending on the difference in hardness. That is, the pressure in the chamber is also different. Therefore, there is a possibility that the type of the obstacle cannot be accurately determined only by comparing the pressure in the chamber with the threshold value. That is, it has been difficult to improve the accuracy of discrimination.

  This invention is made in view of such a situation, and provides the pedestrian collision detection apparatus which can determine accurately whether a collision object is a pedestrian based on a pressure and the speed of a vehicle. For the purpose.

Means for Solving the Problems and Effects of the Invention

  Therefore, as a result of intensive research and trial and error to solve this problem, the present inventor corrected the collision target mass or mass threshold based on the relationship between pressure and time change of pressure, and The inventors have come up with the idea that it is possible to accurately determine whether or not the collision target is a pedestrian without being affected by the difference in the hardness of the object, and the present invention has been completed.

  In other words, the pedestrian collision detection device according to claim 1 is configured such that a bumper sensor that detects a pressure applied to the bumper, a vehicle speed sensor that detects a vehicle speed, a pressure detected by the bumper sensor and the vehicle speed sensor, and a vehicle speed. Based on the relationship between the pressure detected by the bumper sensor and the time variation of the pressure calculated based on the pressure, and the collision target walks based on the corrected mass. Determination means for determining whether or not the person is a person.

  According to this configuration, the mass of the collision target can be calculated based on the pressure and the speed of the vehicle. Further, the mass can be corrected based on the relationship between the pressure and the time change of the pressure. Here, the relationship between the pressure and the time change of the pressure changes depending on the hardness of the collision target. Therefore, by correcting the mass based on the relationship between the pressure and the time change of the pressure, it is possible to suppress the influence due to the difference in the hardness of the collision target. Therefore, it is possible to accurately determine whether or not the collision target is a pedestrian based on the pressure and the speed of the vehicle without being affected by the difference in hardness of the collision target.

  The pedestrian collision detection device according to claim 2 is the pedestrian collision detection device according to claim 1, wherein the determination means has a mass based on an inclination determined by a maximum value of pressure and a maximum value of time change of pressure. It is characterized by correcting. According to this configuration, the mass can be corrected based on the slope determined by the maximum value of pressure and the maximum value of time change of pressure. For example, the gradient of the maximum value of the pressure change with respect to the maximum value of the pressure changes depending on the hardness of the collision target, as shown in FIG. Specifically, it increases as the hardness of the collision target increases. Therefore, by correcting the mass based on the inclination, it is possible to reliably suppress the influence of the hardness of the collision target.

  The pedestrian collision detection device according to claim 3 is the pedestrian collision detection device according to claim 2, wherein the determination means includes a maximum value of pressure and a maximum value of time change of pressure in a collision target having a predetermined hardness. The mass is corrected based on the ratio of the gradient to the reference gradient. According to this configuration, the mass can be corrected based on the ratio of the inclination with respect to the reference inclination. Here, the reference inclination is determined by the maximum value of the pressure and the maximum value of the time change of the pressure in the collision target having the predetermined hardness. That is, the inclination corresponding to the collision target having a predetermined hardness. Therefore, the ratio of the inclination with respect to the reference inclination indicates the hardness of the collision target that has collided. Therefore, by correcting the mass based on the ratio of the inclination with respect to the reference inclination, it is possible to more reliably suppress the influence of the hardness of the collision target.

  The pedestrian collision detection device according to claim 4 is based on a bumper sensor that detects pressure applied to the bumper, a vehicle speed sensor that detects the speed of the vehicle, a pressure detected by the bumper sensor and the vehicle speed sensor, and a speed of the vehicle. Calculates the mass of the collision target, corrects the mass based on the relationship between the pressure detected by the bumper sensor and the time change of the pressure calculated based on the pressure, and corrects the mass and the time change of the pressure and pressure. And determining means for determining whether or not the collision target is a pedestrian based on the relationship.

  According to this configuration, the mass of the collision target can be calculated based on the pressure and the speed of the vehicle. Further, the mass can be corrected based on the relationship between the pressure and the time change of the pressure. The relationship between the pressure and the time change of the pressure changes depending on the hardness of the collision target. Therefore, by correcting the mass based on the relationship between the pressure and the time change of the pressure, it is possible to suppress the influence due to the difference in the hardness of the collision target. Moreover, since the determination is made based on the relationship between the corrected mass and the pressure and the time change of the pressure, the determination accuracy can be improved as compared with the case where the determination is made based only on the corrected mass.

The pedestrian collision detection device according to claim 5 is the pedestrian collision detection device according to claim 4, wherein the determination means is based on an inclination determined by a maximum value of pressure and a maximum value of time change of pressure. It is characterized by correcting. According to this configuration, the determination can be made based on the slope determined by the maximum value of the pressure and the maximum value of the time change of the pressure. The slope determined by the maximum value of pressure and the maximum value of time change of pressure changes depending on the hardness of the collision target. Therefore, it can be reliably determined based on the hardness of the collision target.

The pedestrian collision detection apparatus according to claim 6 is the pedestrian collision detection apparatus according to claim 5, wherein the determination means includes a maximum value of pressure in a collision target having a predetermined hardness and a maximum value of time change of pressure. The mass is corrected based on the ratio of the gradient to the reference gradient . According to this configuration, the determination can be made based on the ratio of the inclination to the reference inclination. The reference inclination is an inclination corresponding to a collision target having a predetermined hardness. Therefore, the ratio of the inclination with respect to the reference inclination indicates the hardness of the collision target that has collided. Therefore, the determination can be made more reliably based on the hardness of the collision target.

  The pedestrian collision detection device according to claim 7 is based on a bumper sensor that detects pressure applied to the bumper, a vehicle speed sensor that detects the speed of the vehicle, a pressure detected by the bumper sensor and the vehicle speed sensor, and a speed of the vehicle. A comparison that calculates the mass of the collision target and corrects the mass threshold based on the relationship between the pressure detected by the bumper sensor and the time variation of the pressure calculated based on the pressure, and compares the mass with the corrected mass threshold And determining means for determining whether or not the collision target is a pedestrian based on the result.

  According to this configuration, the mass of the collision target can be calculated based on the pressure and the speed of the vehicle. Further, the mass threshold value can be corrected based on the relationship between the pressure and the time change of the pressure. The relationship between the pressure and the time change of the pressure changes depending on the hardness of the collision target. Therefore, by correcting the mass threshold based on the relationship between the pressure and the time change of the pressure, it is possible to suppress the influence due to the difference in the hardness of the collision target. Therefore, it is possible to accurately determine whether or not the collision target is a pedestrian based on the pressure and the speed of the vehicle without being affected by the difference in hardness of the collision target.

  The pedestrian collision detection device according to claim 8 is the pedestrian collision detection device according to claim 7, wherein the determination means has a mass based on an inclination determined by a maximum value of pressure and a maximum value of time change of pressure. The threshold value is corrected. According to this configuration, the mass threshold value can be corrected based on the slope determined by the maximum pressure value and the maximum pressure change over time. The slope determined by the maximum value of pressure and the maximum value of time change of pressure changes depending on the hardness of the collision target. Therefore, by correcting the mass threshold based on the inclination, it is possible to reliably suppress the influence of the hardness of the collision target.

  The pedestrian collision detection device according to claim 9 is the pedestrian collision detection device according to claim 8, wherein the determination means includes a maximum value of pressure in a collision target having a predetermined hardness and a maximum value of time change of pressure. And the mass threshold value is corrected based on the ratio of the slope to the reference slope. According to this configuration, the mass threshold value can be corrected based on the ratio of the inclination with respect to the reference inclination. The reference inclination is an inclination corresponding to a collision target having a predetermined hardness. Therefore, the ratio of the inclination with respect to the reference inclination indicates the hardness of the collision target that has collided. Therefore, by correcting the mass threshold based on the ratio of the inclination with respect to the reference inclination, it is possible to more reliably suppress the influence of the hardness of the collision target.

  The pedestrian collision detection device according to claim 10 is based on a bumper sensor that detects pressure applied to the bumper, a vehicle speed sensor that detects the speed of the vehicle, a pressure detected by the bumper sensor and the vehicle speed sensor, and a speed of the vehicle. A comparison that calculates the mass of the collision target and corrects the mass threshold based on the relationship between the pressure detected by the bumper sensor and the time variation of the pressure calculated based on the pressure, and compares the mass with the corrected mass threshold It has a determination means which determines whether a collision object is a pedestrian based on a result and the relationship between a pressure and the time change of a pressure, It is characterized by the above-mentioned.

  According to this configuration, the mass of the collision target can be calculated based on the pressure and the speed of the vehicle. Further, the mass threshold value can be corrected based on the relationship between the pressure and the time change of the pressure. The relationship between the pressure and the time change of the pressure changes depending on the hardness of the collision target. Therefore, by correcting the mass threshold based on the relationship between the pressure and the time change of the pressure, it is possible to suppress the influence due to the difference in the hardness of the collision target. In addition, since the determination is made based on the comparison result between the mass and the corrected mass threshold value and the relationship between the pressure and the time change of the pressure, the determination is made based only on the comparison result comparing the mass and the corrected mass threshold value. Compared to the case, the accuracy of determination can be improved.

The pedestrian collision detection device according to claim 11 is the pedestrian collision detection device according to claim 10, wherein the determination means is based on an inclination determined by a maximum value of pressure and a maximum value of time change of pressure. The mass threshold value is corrected. According to this configuration, the determination can be made based on the slope determined by the maximum value of the pressure and the maximum value of the time change of the pressure. The slope determined by the maximum value of pressure and the maximum value of time change of pressure changes depending on the hardness of the collision target. Therefore, it can be reliably determined based on the hardness of the collision target.

The pedestrian collision detection device according to claim 12 is the pedestrian collision detection device according to claim 11, wherein the determination means includes a maximum value of pressure in a collision target having a predetermined hardness and a maximum value of time change of pressure. And the mass threshold value is corrected based on the ratio of the slope to the reference slope . According to this configuration, the determination can be made based on the ratio of the inclination to the reference inclination. The reference inclination is an inclination corresponding to a collision target having a predetermined hardness. Therefore, the ratio of the inclination with respect to the reference inclination indicates the hardness of the collision target that has collided. Therefore, the determination can be made more reliably based on the hardness of the collision target.

  The pedestrian collision detection device according to claim 13 is the pedestrian collision detection device according to claims 3, 6, 9 and 12, wherein the determination means corrects the reference inclination based on the speed of the vehicle. And According to this configuration, the reference inclination can be corrected based on the vehicle speed. As shown in FIG. 10, the slope of the maximum value of the pressure change with respect to the maximum value of the pressure changes depending on not only the hardness of the collision target but also the speed of the vehicle at the time of the collision. Specifically, it increases as the speed of the vehicle at the time of collision increases. Therefore, by correcting the reference inclination based on the vehicle speed, it is possible to suppress the influence due to the difference in the vehicle speed at the time of the collision.

  The slope and the reference slope referred to here may be the slope of the maximum value of the pressure change with respect to the maximum value of the pressure, or the slope of the maximum value of the pressure with respect to the maximum value of the time change of the pressure. Good.

  Next, an embodiment is given and this invention is demonstrated in detail. In this embodiment, the example which applied the pedestrian collision detection apparatus which concerns on this invention to the airbag apparatus for protecting the pedestrian who collided with the bumper is shown.

(First embodiment)
First, the configuration of the airbag device will be described with reference to FIGS. 1 and 2. Here, FIG. 1 is a block diagram of the airbag apparatus in the first embodiment. FIG. 2 is a schematic layout diagram of the airbag apparatus. FIG. 3 is a cross-sectional view around the bumper.

  As shown in FIG.1 and FIG.2, the airbag apparatus 1 is an apparatus which protects the pedestrian who collided with the bumper. The airbag device 1 includes a pedestrian collision detection device 2 and a pedestrian protection device 3.

  The pedestrian collision detection device 2 is a device that detects a pedestrian collision with the bumper 4. The pedestrian collision detection device 2 includes a bumper sensor 20, a vehicle speed sensor 21, and a controller 22 (determination means).

  The bumper sensor 20 is a sensor that detects pressure applied to the bumper 4. Incidentally, as shown in FIGS. 2 and 3, the bumper 4 includes a bumper cover 40 and a bumper absorber 41 having a substantially rectangular tube shape. A bumper reinforcement 44 is fixed to the front ends of the side members 42 and 43 constituting the vehicle frame. The bumper cover 40 is fixed to a vehicle body such as a fender at a position almost in contact with the bumper absorber 41. The bumper sensor 20 is disposed on the inner peripheral surface of the bumper absorber 41 on the bumper reinforcement 44 side, and is connected to the controller 22.

  The vehicle speed sensor 21 is a sensor that detects the speed of the vehicle. The vehicle speed sensor 21 is disposed near the front tire and is connected to the controller 22.

  The controller 22 is a device that includes a microcomputer that determines whether or not the object colliding with the vehicle is a pedestrian based on the outputs of the bumper sensor 20 and the vehicle speed sensor 21. Moreover, when it determines with the colliding target object being a pedestrian, it is also an apparatus which outputs the starting signal for starting the pedestrian protection apparatus 3. FIG. The controller 22 is disposed at the center of the vehicle.

  The pedestrian protection device 3 is a device that is deployed in front of the front window and protects a pedestrian that has collided with the bumper 4. The pedestrian protection device 3 is disposed around the front pillar and is connected to the controller 22.

  Next, the operation of the airbag apparatus will be described with reference to FIGS. 2 and 4 to 6. Here, FIG. 4 is a flowchart regarding the operation of the pedestrian collision detection apparatus. FIG. 5 is a graph showing the relationship between the effective mass maximum value and the effective mass change maximum value with respect to the difference in hardness of the collision target. FIG. 6 is a graph showing the relationship between the effective mass maximum value and the effective mass change maximum value with respect to the difference in vehicle speed at the time of collision.

  In FIG. 2, when power is supplied to the airbag device 1, the pedestrian collision detection device 2 and the pedestrian protection device 3 start to operate.

  As shown in FIG. 4, the controller 22 initializes various variables set inside (step S100). Specifically, vehicle speed sensor output V, bumper sensor output P (t), effective mass M (t), effective mass change M ′ (t), effective mass maximum value Mmax, effective mass change maximum value M′max, reference The inclination K0, the inclination K1, and the correction coefficient α are initialized.

  Thereafter, the controller 22 reads the output of the vehicle speed sensor 21 and sets it to the vehicle speed sensor output V (step S101). Then, it is determined whether or not the set vehicle speed sensor output V is not less than a preset pedestrian determination vehicle speed minimum value Vmin and not more than a pedestrian determination vehicle speed maximum value Vmax (step S102). Here, the pedestrian determination vehicle speed minimum value Vmin and the pedestrian protection vehicle speed maximum value Vmax define a vehicle speed range for determining whether or not the vehicle has collided with a pedestrian. By the way, when the speed of the vehicle at the time of the collision is low, the impact applied to the pedestrian is small, and the necessity to activate the pedestrian protection device 3 is low. In addition, if the pedestrian protection device 3 is activated under such conditions, the operation of the vehicle may be hindered. On the other hand, when the speed of the vehicle at the time of the collision is high, there is a high possibility that the pedestrian is skipped, and the pedestrian protection device 3 cannot protect it. Therefore, in consideration of such conditions, the minimum pedestrian determination vehicle speed Vmin is set to the minimum vehicle speed at which the pedestrian protection device 3 is activated. Further, the pedestrian determination vehicle speed maximum value Vmax is set to the maximum vehicle speed value at which the pedestrian protection device 3 is activated.

  In step S102, when the vehicle speed sensor output V is less than the pedestrian determination vehicle speed minimum value Vmin or exceeds the pedestrian determination vehicle speed maximum value Vmax, the process returns to step S101. On the other hand, in step S102, when the vehicle speed sensor output V is not less than the pedestrian determination vehicle speed minimum value Vmin and not more than the pedestrian determination vehicle speed maximum value Vmax, the controller 22 reads the output of the bumper sensor 20 and outputs the bumper sensor output. P (t) is set (step S103).

  Thereafter, the controller 22 calculates an effective mass corresponding to the mass of the object that has collided with the bumper 4 from the bumper sensor output P (t) and the vehicle speed sensor output V, and the effective mass M (t). (Step S104).

  By the way, the pressure applied to the bumper 4 by the collision depends on the collision energy. Approximately, it can be considered proportional to the collision energy. Here, considering the vehicle side as a reference, the collision energy is the kinetic energy of the collided object, and is proportional to the mass of the collision and the square of the velocity at the time of the collision. The pressure applied to the bumper 4 is the bumper sensor output P (t), and the vehicle speed at the time of the collision is the vehicle speed sensor output V. Therefore, as shown in Equation 1, the effective mass M (t) can be calculated based on the bumper sensor output P (t) and the vehicle speed sensor output V.

  Thereafter, the controller 22 calculates an effective mass change, which is a time change of the effective mass, from the calculated effective mass M (t) based on Equation 2, and sets the effective mass change M ′ (t) (S105).

  Then, the controller 22 determines whether or not the set effective mass change M ′ (t) is greater than or equal to the effective mass change maximum value M′max (step S106).

  In step S106, when the effective mass change M ′ (t) is equal to or larger than the effective mass change maximum value M′max, the controller 22 substitutes the value of the effective mass change M ′ (t) into the effective mass change maximum value M′max. And update (step S107). On the other hand, when the effective mass change M ′ (t) is less than the effective mass change maximum value M′max in step S106 or when the effective mass change maximum value M′max is updated in step S107, the controller 22 determines whether the set effective mass M (t) is greater than or equal to the effective mass maximum value Mmax (step S108).

  When the effective mass M (t) is greater than or equal to the effective mass maximum value Mmax in step S108, the controller 22 updates the effective mass M (t) by substituting the effective mass M (t) for the effective mass maximum value Mmax (step S109). On the other hand, when the effective mass M (t) is less than the effective mass maximum value Mmax in step S108, or when the effective mass maximum value Mmax is updated in step S109, the controller 22 sets the effective mass M set. It is determined whether (t) is 80% or less of the effective mass maximum value Mmax (step S110).

  In step S110, when the effective mass M (t) exceeds 80% of the effective mass maximum value Mmax, the process returns to step S101. On the other hand, when the effective mass M (t) is equal to or less than 80% of the effective mass maximum value Mmax in step S110, the controller 22 calculates the effective mass maximum value Mmax and the effective mass change maximum value M′max based on Equation 3. Then, an inclination that is a ratio of the effective mass change maximum value M′max to the effective mass maximum value Mmax is calculated and set to the inclination K1 (step S111).

  By the way, the relationship between the pressure applied to the bumper 4 at the time of a collision and the pressure change changes depending on the hardness of the collided object. Specifically, the slope of the maximum pressure change value with respect to the maximum pressure value changes depending on the hardness of the collided object. More specifically, it increases as the hardness of the collided object increases. Here, as shown in Equation 1, the effective mass M (t) is approximately calculated as being proportional to the bumper sensor output P (t). Therefore, the relationship between the effective mass M (t) and the effective mass change M ′ (t) is the same as the relationship between the pressure applied to the bumper 4 and the pressure change. Therefore, the gradient of the effective mass change maximum value M′max with respect to the effective mass maximum value Mmax also increases as the hardness of the collided object increases as shown in FIG.

  Thereafter, the controller 22 reads the gradient of the effective mass change maximum value M′max with respect to the effective mass maximum value Mmax from the preset table T0 based on the vehicle speed sensor output V, and sets it as the reference gradient K0 (step S112). ). Here, the table T0 stores, for each vehicle speed, the gradient of the effective mass change maximum value M′max with respect to the effective mass maximum value Mmax when a reference object having a predetermined hardness collides. . Incidentally, the gradient of the effective mass change maximum value M′max with respect to the effective mass maximum value Mmax varies depending on the speed of the vehicle at the time of the collision, as shown in FIG. 6. Specifically, it increases as the speed of the vehicle at the time of collision increases. The controller 22 reads the inclination corresponding to the vehicle speed sensor output V from the stored inclinations and sets it as the reference inclination K0. Thereby, the inclination corresponding to the reference object having a predetermined hardness, corrected based on the speed of the vehicle, is set as the reference inclination K0.

  Then, the controller 22 reads a correction coefficient for correcting the effective mass maximum value Mmax from the preset table T1 based on the reference inclination K0 and the inclination K1, and sets the correction coefficient α to the correction coefficient α (step S113). Here, the table T1 stores a correction coefficient for correcting the effective mass maximum value Mmax for each ratio K1 / K0 of the gradient K1 with respect to the reference gradient K0. Incidentally, the reference inclination K0 is an inclination corresponding to a reference object having a predetermined hardness, corrected based on the speed of the vehicle. Therefore, the ratio K1 / K0 of the inclination K1 with respect to the reference inclination K0 indicates the hardness of the collided object. The controller 22 reads out the correction coefficient corresponding to the ratio K1 / K0 from the stored correction coefficients and sets it as the correction coefficient α. Thereby, the correction coefficient corresponding to the hardness of the collided object is set as the correction coefficient α. For example, when the ratio K1 / K0 is less than 1, that is, when the hardness of the collided object is softer than the hardness of the reference object, the effective mass maximum value Mmax is reduced, so that the effective mass maximum value Mmax is largely corrected. Such a correction coefficient is set.

  Thereafter, the controller 22 multiplies the effective mass maximum value Mmax by the correction coefficient α, and determines whether or not the effective mass threshold value Mth or more (step S114). Here, the effective mass threshold value Mth prescribes an effective mass threshold value for determining whether or not the collided object is a pedestrian. The effective mass threshold Mth is set to a value that can distinguish the effective mass of a pedestrian from the effective mass of another object.

  In step S114, when the corrected effective mass maximum value αMmax is equal to or greater than the effective mass threshold, the controller 22 determines that the vehicle has collided with the pedestrian, and outputs an activation signal for activating the pedestrian protection device 3. . When the controller 22 outputs the activation signal, the pedestrian protection device 3 is deployed to protect the colliding pedestrian. On the other hand, in step S114, when the corrected effective mass maximum value αMmax is less than the effective mass threshold value Mth, the controller 22 determines that the colliding object is not a pedestrian. At this time, the activation signal is not output.

  Finally, the effect will be described. According to the pedestrian collision detection device 2 of the first embodiment, the effective mass of the collided object can be calculated based on the pressure applied to the bumper 4 and the speed of the vehicle. Further, the effective mass maximum value can be corrected based on the ratio of the inclination to the reference inclination. As described above, the reference inclination is an inclination corresponding to a reference object having a predetermined hardness. Therefore, the ratio of the inclination with respect to the reference inclination indicates the hardness of the collided object. Therefore, the influence of the hardness of the collided object can be suppressed by correcting the effective mass maximum value based on the ratio of the inclination to the reference inclination. Thereby, it is possible to accurately determine whether or not the collided object is a pedestrian based on the pressure and the speed of the vehicle without being affected by the difference in hardness of the collided object.

  Further, according to the pedestrian collision detection device 2 of the first embodiment, the reference inclination can be corrected based on the vehicle speed by the table T0. As shown in FIG. 6, the gradient of the maximum effective mass change value with respect to the maximum effective mass value changes depending on not only the hardness of the collided object but also the vehicle degree at the time of the collision. Specifically, it increases as the speed of the vehicle at the time of collision increases. Therefore, by correcting the reference inclination based on the vehicle speed, it is possible to suppress the influence due to the difference in the vehicle speed at the time of the collision.

(Second Embodiment)
Next, the airbag apparatus of 2nd Embodiment is demonstrated. The airbag apparatus of 2nd Embodiment is the structure same as the airbag apparatus of 1st Embodiment, and changes only a part of process. Specifically, the airbag device of the first embodiment is determined based on the effective mass and the inclination, that is, the determination based on the effective mass and the hardness. It is.

  First, the operation of the airbag device will be described with reference to FIG. Here, FIG. 7 is a flowchart regarding the operation of the pedestrian collision detection apparatus according to the second embodiment. Here, only the determination process which is a different part from the airbag apparatus of 1st Embodiment is demonstrated, and description other than the required part is abbreviate | omitted about a common part. In addition, the same code | symbol is attached | subjected and demonstrated to the element same as embodiment mentioned above.

  In FIG. 7, Steps S200 to S213 are the same as Steps S100 to S113 in the first embodiment, and thus description thereof is omitted.

  As shown in FIG. 7, the controller 22 multiplies the effective mass maximum value Mmax by the correction coefficient α, and determines whether or not the effective mass threshold value Mth or more (S214). Here, the effective mass threshold value Mth is set to a value that can distinguish the effective mass of a pedestrian from the effective mass of another object.

  In step S214, when the corrected effective mass maximum value αMmax is equal to or greater than the effective mass threshold value Mth, the controller 22 determines that the ratio K1 / K0 is equal to or greater than the preset ratio threshold minimum value Kth1 and the ratio threshold maximum value Kth2. It is determined whether or not the following is true (S215). Here, the ratio threshold minimum value Kth1 and the ratio threshold maximum value Kth2 define ratio thresholds for determining whether or not the colliding target object is a pedestrian. As described above, since the ratio K1 / K0 indicates the hardness of the collided object, the ratio threshold minimum value Kth1 and the ratio threshold maximum value Kth2 also indicate whether the collided object is a pedestrian. A threshold value corresponding to the hardness for determination is defined. The ratio threshold minimum value Kth1 is set to a minimum value that can distinguish between the hardness of a pedestrian and the hardness of another object. The ratio threshold maximum value Kth2 is set to a maximum value that can distinguish between the hardness of a pedestrian and the hardness of another object.

  In step S215, when the ratio K1 / K0 is not less than the ratio threshold minimum value Kth1 and not more than the ratio threshold maximum value Kth2, the controller 22 determines that the colliding object is a pedestrian, and sets the pedestrian protection device 3 to A start signal for starting is output. When the controller 22 outputs the activation signal, the pedestrian protection device 3 is deployed to protect the colliding pedestrian. On the other hand, when the corrected effective mass maximum value αMmax is less than the effective mass threshold value Mth in step S214, or in step S215, the ratio K1 / K0 is less than the ratio threshold minimum value Kth1 or the ratio threshold maximum value Kth2 The controller 22 determines that the collided object is not a pedestrian. At this time, the activation signal is not output.

  Finally, the effect will be described. According to the pedestrian collision detection device 2 of the second embodiment, the effective mass of the collided object can be calculated based on the pressure of the bumper 4 and the speed of the vehicle. Further, the effective mass maximum value can be corrected based on the ratio between the reference inclination and the inclination. As described above, the ratio of the inclination with respect to the reference inclination indicates the hardness of the collided object. Therefore, by correcting the effective mass maximum value based on the ratio between the reference inclination and the inclination, it is possible to suppress the influence due to the difference in hardness of the collided object. Moreover, since the determination is made based on the corrected effective mass maximum value and the ratio of the inclination with respect to the reference inclination, the determination accuracy can be improved as compared with the case where the determination is made based only on the corrected effective mass maximum value.

(Third embodiment)
Next, the airbag apparatus of 3rd Embodiment is demonstrated. The airbag apparatus of 3rd Embodiment is the structure same as the airbag apparatus of 1st Embodiment, and changes only a part of process. Specifically, the airbag device of the first embodiment is determined after correcting the effective mass, whereas it is determined by correcting the mass threshold.

  First, the operation of the airbag device will be described with reference to FIG. Here, FIG. 8 is a flowchart regarding the operation of the pedestrian collision detection apparatus according to the third embodiment. Here, only the determination process which is a different part from the airbag apparatus of 1st Embodiment is demonstrated, and description other than the required part is abbreviate | omitted about a common part. In addition, the same code | symbol is attached | subjected and demonstrated to the element same as embodiment mentioned above.

  As shown in FIG. 8, the controller 22 initializes various variables set inside (step S300). Specifically, vehicle speed sensor output V, bumper sensor output P (t), effective mass M (t), effective mass change M ′ (t), effective mass maximum value Mmax, effective mass change maximum value M′max, reference The inclination K0, the inclination K1, and the correction coefficient β are initialized.

  Subsequent steps S301 to S312 are the same as steps S101 to S112 in the first embodiment, and a description thereof will be omitted.

  The controller 22 reads out a correction coefficient for correcting the effective mass threshold value Mth from the preset table T2 based on the reference inclination K0 and the inclination K1, and sets it as the correction coefficient β (step S313). Here, the table T2 stores a correction coefficient for correcting the effective mass threshold value Mth for each ratio K1 / K0 of the gradient K1 with respect to the reference gradient K0. Incidentally, as described above, the ratio K1 / K0 of the inclination K1 with respect to the reference inclination K0 indicates the hardness of the collided object. The controller 22 reads out the correction coefficient corresponding to the ratio K1 / K0 from the stored correction coefficients and sets it as the correction coefficient β. Thereby, the correction coefficient corresponding to the hardness of the collided object is set as the correction coefficient β. For example, when the ratio K1 / K0 is less than 1, that is, when the hardness of the collided object is softer than the hardness of the reference object, the effective mass maximum value Mmax is reduced, so that the effective mass threshold value Mth is corrected to be small. Such a correction coefficient is set.

  Thereafter, the controller 22 multiplies the effective mass threshold value Mth by the correction coefficient β, and determines whether or not the maximum effective mass value Mmax is equal to or greater than the corrected effective mass threshold value βMth (step S314). Here, the effective mass threshold value Mth prescribes an effective mass threshold value for determining whether or not the collided object is a pedestrian. The effective mass threshold Mth is set to a value that can distinguish the effective mass of a pedestrian from the effective mass of another object.

  In step S314, when the effective mass maximum value Mmax is equal to or greater than the corrected effective mass threshold value βMth, the controller 22 determines that the collided object is a pedestrian and activates the pedestrian protection device 3. Is output. When the controller 22 outputs the activation signal, the pedestrian protection device 3 is deployed to protect the colliding pedestrian. On the other hand, in step S314, when the effective mass maximum value Mmax is less than the corrected effective mass threshold value βMth, the controller 22 determines that the colliding object is not a pedestrian. At this time, the activation signal is not output.

  Finally, the effect will be described. According to the pedestrian collision detection device 2 of the third embodiment, the effective mass of the collided object can be calculated based on the pressure applied to the bumper 4 and the speed of the vehicle. Further, the effective mass threshold value can be corrected based on the ratio of the inclination with respect to the reference inclination. The reference inclination is an inclination corresponding to a reference object having a predetermined hardness. Therefore, the ratio of the inclination with respect to the reference inclination indicates the hardness of the collided object. Therefore, by correcting the effective mass threshold based on the ratio of the inclination with respect to the reference inclination, it is possible to suppress the influence of the hardness of the collided object. Thereby, based on the pressure and the speed of the vehicle, it is possible to accurately determine whether or not the collided object is a pedestrian without being affected by the difference in hardness of the collided object.

In the third embodiment, an example is given in which it is determined whether or not the colliding target object is a pedestrian based on the effective mass maximum value and the corrected effective mass threshold. However, the present invention is not limited to this. . Even in this case, the determination may be made based on the ratio of the inclination to the reference inclination, as in the second embodiment. The same effect as in the second embodiment can be obtained.

  In the first to third embodiments, examples using the tables T0 to T2 are given, but the present invention is not limited to this. You may make it calculate the value required each time using a calculation formula.

It is a block diagram of the airbag apparatus in a 1st embodiment. It is a typical layout view of an airbag device. It is sectional drawing of a bumper periphery. It is a flowchart regarding operation | movement of a pedestrian collision detection apparatus. It is a graph which shows the relationship between the effective mass maximum value with respect to the difference in the hardness of a collision target, and an effective mass change maximum value. It is a graph which shows the relationship between the effective mass maximum value with respect to the difference in the speed of the vehicle at the time of a collision, and an effective mass change maximum value. It is a flowchart regarding operation | movement of the pedestrian collision detection apparatus in 2nd Embodiment. It is a flowchart regarding operation | movement of the pedestrian collision detection apparatus in 3rd Embodiment. It is a graph which shows the relationship between the maximum value of the pressure of a bumper sensor with respect to the difference in the hardness of a collision target, and the maximum value of the time change of a pressure. It is a graph which shows the relationship between the maximum value of the pressure of a bumper sensor with respect to the difference in the speed of the vehicle at the time of a collision, and the maximum value of the time change of a pressure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Airbag apparatus, 2 ... Pedestrian collision detection apparatus, 20 ... Bumper sensor, 21 ... Vehicle speed sensor, 22 ... Controller (determination means), 3 ... Pedestrian protection apparatus 4 ... Bumper, 40 ... Bumper cover, 41 ... Bumper absorber, 42, 43 ... Side member, 44 ... Bumper reinforcement

Claims (13)

  A bumper sensor that detects pressure applied to the bumper, a vehicle speed sensor that detects the speed of the vehicle, and calculates the mass of the collision target based on the pressure detected by the bumper sensor and the vehicle speed sensor and the speed of the vehicle, The mass is corrected based on the relationship between the pressure detected by the bumper sensor and the time change of the pressure calculated based on the pressure, and whether the collision target is a pedestrian based on the corrected mass. A pedestrian collision detection device comprising: a determination unit that determines whether or not.   The pedestrian collision detection device according to claim 1, wherein the determination unit corrects the mass based on an inclination determined by a maximum value of the pressure and a maximum value of the time change of the pressure.   The determination means has a reference inclination determined by a maximum value of the pressure and a maximum value of the time change of the pressure in a collision target having a predetermined hardness, and corrects the mass based on a ratio of the inclination to the reference inclination. The pedestrian collision detection device according to claim 2, wherein:   A bumper sensor that detects pressure applied to the bumper, a vehicle speed sensor that detects the speed of the vehicle, and calculates the mass of the collision target based on the pressure detected by the bumper sensor and the vehicle speed sensor and the speed of the vehicle, The mass is corrected based on the relationship between the pressure detected by the bumper sensor and the time change of the pressure calculated based on the pressure, the corrected mass, and the time change of the pressure and the pressure A pedestrian collision detection apparatus comprising: a determination unit that determines whether or not the collision target is a pedestrian based on the relationship. The pedestrian collision detection device according to claim 4, wherein the determination unit corrects the mass based on an inclination determined by a maximum value of the pressure and a maximum value of the time change of the pressure. The determination means has a reference inclination determined by a maximum value of the pressure and a maximum value of the time change of the pressure in a collision target having a predetermined hardness, and corrects the mass based on a ratio of the inclination to the reference inclination. The pedestrian collision detection device according to claim 5.   A bumper sensor that detects pressure applied to the bumper, a vehicle speed sensor that detects the speed of the vehicle, and calculates the mass of the collision target based on the pressure detected by the bumper sensor and the vehicle speed sensor and the speed of the vehicle, Based on the comparison result of correcting the mass threshold based on the relationship between the pressure detected by the bumper sensor and the time change of the pressure calculated based on the pressure, and comparing the mass with the corrected mass threshold. A pedestrian collision detection device, comprising: a determination unit configured to determine whether or not the collision target is a pedestrian.   The pedestrian collision detection device according to claim 7, wherein the determination unit corrects the mass threshold based on an inclination determined by a maximum value of the pressure and a maximum value of the time change of the pressure.   The determination means has a reference gradient determined by a maximum value of the pressure and a maximum value of time change of the pressure in a collision target having a predetermined hardness, and determines the mass threshold based on a ratio of the gradient to the reference gradient. It correct | amends, The pedestrian collision detection apparatus of Claim 8 characterized by the above-mentioned.   A bumper sensor that detects pressure applied to the bumper, a vehicle speed sensor that detects the speed of the vehicle, and calculates the mass of the collision target based on the pressure detected by the bumper sensor and the vehicle speed sensor and the speed of the vehicle, A comparison result of correcting the mass threshold based on the relationship between the pressure detected by the bumper sensor and the time change of the pressure calculated based on the pressure, and comparing the mass and the corrected mass threshold; and A pedestrian collision detection apparatus comprising: a determination unit that determines whether or not the collision target is a pedestrian based on a relationship between the pressure and the time change of the pressure. The pedestrian collision detection device according to claim 10, wherein the determination unit corrects the mass threshold based on an inclination determined by a maximum value of the pressure and a maximum value of the time change of the pressure. The determination means has a reference gradient determined by a maximum value of the pressure and a maximum value of time change of the pressure in a collision target having a predetermined hardness, and determines the mass threshold based on a ratio of the gradient to the reference gradient. It correct | amends , The pedestrian collision detection apparatus of Claim 11 characterized by the above-mentioned.   The pedestrian collision detection device according to claim 3, 6, 9, or 12, wherein the determination unit corrects the reference inclination based on a speed of the vehicle.

Images