JP4449628B2 - Pedestrian collision determination device - Google Patents

Description

  The present invention relates to a pedestrian collision determination device that determines whether or not a collision object is a pedestrian.

  Conventionally, in a pedestrian protection device that determines a collision with a pedestrian based on a bumper sensor provided on a front bumper and a collision sensor provided on a front hood, the output load of the bumper sensor is a predetermined value or more, and the collision sensor is A technique is known in which a collision object is determined to be a pedestrian when a collision signal indicating a collision state is output (see, for example, Patent Document 1).

In addition, a technique is known in which a collision with a pedestrian is determined based on a load disposed in or around the front bumper or an output value of a displacement sensor, and the hood is flipped up when the collision with the pedestrian is determined. (For example, refer to Patent Document 2). In this conventional technology, in the case of a collision with a pedestrian, the output load is small and the load rising time (duration) is short compared to a heavy impact object such as a vehicle or a utility pole. The collision object is determined to be a pedestrian on the condition that the output load is within a certain range and the duration is not more than a predetermined value.
Patent No. 2920284 Japanese Patent Laid-Open No. 11-28994

  By the way, in the case of a light-weight collision object such as a shopping cart or a trash can that contains a heavy object of the same level as or less than that of a pedestrian, a load value equivalent to that of a collision with a pedestrian is output from the load sensor. Therefore, it is difficult to determine such a light-weight collision object and a pedestrian. In this regard, the above-described conventional technology (Patent Document 2) provides a determination method for separating a heavy impact object and a pedestrian, but provides a determination method for effectively separating a light-weight collision object and a pedestrian. It was not a thing.

  Then, an object of this invention is to provide the pedestrian collision determination apparatus which enables the effective separation of a light weight collision object and a pedestrian.

In order to solve the above-described problem, according to one aspect of the present invention, a load detection unit that detects and outputs a load applied to the vehicle from outside, and a second predetermined after the load applied to the vehicle from outside exceeds a first predetermined value. A pedestrian collision determination that determines whether or not the collision object is a pedestrian based on the output load of the load detection means and the duration. In the device
Load integral value for calculating the load integral value when the duration exceeds a lower limit threshold value, and the load integral value is calculated when the load detected by the load detection means exceeds a third predetermined value. A value calculating means,
A two-dimensional map in which a closed region defined by the lower and upper thresholds of the duration and the lower and upper thresholds of the load integral value is defined;
Provided is a pedestrian collision determination device characterized in that a collision object is determined to be a pedestrian when a point determined by the duration time and the load integral value belongs to a closed region in the two-dimensional map. The

In this aspect, the lower limit threshold value may change according to the load integral value. In this case, the lower limit threshold value may take a larger value as the load integral value is larger. The load detection means may include a pressure sensor.

Further, in this aspect, a two-dimensional map in which a closed region defined by the lower limit threshold and the upper limit threshold of the duration and the lower limit threshold and the upper limit threshold of the load integral value is defined,
When a point determined by the duration and the load integral value belongs to a closed region in the two-dimensional map, the collision object may be determined to be a pedestrian.

  In each of the above aspects, the duration calculation means may calculate the duration based on an output state of an ON signal of a touch sensor mounted at a predetermined position of the vehicle body.

  ADVANTAGE OF THE INVENTION According to this invention, the pedestrian collision determination apparatus which enables the effective separation of a light weight collision object and a pedestrian can be obtained.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is a system configuration diagram showing an embodiment of a pedestrian collision determination apparatus according to the present invention. The pedestrian collision determination apparatus according to the present embodiment is configured around an electronic control apparatus 10 (hereinafter referred to as “ECU 10”). An occupant protection device 20 such as an active hood or a hood airbag is connected to the ECU 10.

  The active hood is a protective device that operates so that the rear end of the hood of the vehicle is lifted under the control of the ECU 10. When the active hood is activated, the hood panel is tilted so that the rear side of the vehicle is higher than normal. The active hood prevents the impacting object from moving backward after the collision by the inclined hood panel, and at the same time, the hood panel is deformed, thereby reducing the impact on the impacting object.

  The hood airbag is a protective device that is deployed and operated under the control of the ECU 10. The hood airbag may be provided, for example, in the vicinity of the front end (cowl portion) of the windshield of the vehicle, and is deployed and operated so as to cover at least the front end portion of the windshield and the front pillar (A pillar). The hood airbag functions to restrain and protect the collision object and to reduce the impact on the collision object.

  The present invention is not particularly limited to the configuration and operation of the occupant protection device 20 as described above, and the occupant protection device 20 is not limited to an active hood or a hood airbag. A protective net provided further forward may be included.

  A load sensor 32 is connected to the ECU 10. As shown in FIG. 2, the load sensor 32 is mounted in front of the vehicle (for example, in the left and right front side members, bumper reinforcements, and bumpers) and outputs an output signal corresponding to the load applied to the vehicle from the outside. For example, the load sensor 32 may be an optical fiber sensor, a pressure sensor, a strain gauge, or the like that is provided on a bumper of a vehicle body and detects a load acting on the front surface of the bumper. The output signal of the load sensor 32 is input to the ECU 10 at predetermined intervals through predetermined processing (for example, filter processing) as necessary.

  A touch sensor 34 is connected to the ECU 10. As shown in FIG. 2, the touch sensor 34 is mounted in front of the vehicle (typically in a bumper) and generates an ON signal when an input (load or deformation) exceeding a set value is received. In the case of (when the input is less than the set value), an off signal is generated. An on / off signal of the touch sensor 34 is supplied to the ECU 10.

  FIG. 3 is a functional block diagram of the ECU 10 of the present embodiment. The ECU 10 of the present embodiment includes a load value calculation unit 12, a duration calculation unit 14, a pedestrian determination unit 16, and a control signal generation unit 18.

  The load value calculation unit 12 calculates a load applied to the vehicle from the outside and / or an integral value thereof based on an output signal from the load sensor 32 input every predetermined cycle. When calculating the integral value, the start point of the integration interval may be a point in time when the load calculated by the load value calculation unit 12 exceeds the third predetermined value, or simply from the touch sensor 34. It may be the time when the ON signal is output.

  The duration calculation unit 14 calculates the duration of a state in which the load applied to the vehicle from the outside exceeds the first predetermined value and does not fall below the second predetermined value. Most simply, the duration calculation unit 14 calculates the duration in which the ON signal is continuously output from the touch sensor 34 (in this case, the first predetermined value = the second predetermined value = the set value). ). However, the duration calculation unit 14 may calculate the duration based on an output signal from the load sensor 32 instead of or in addition to the touch sensor 34.

  The calculation results of the load value calculation unit 12 and the duration calculation unit 14 are input to the pedestrian determination unit 16. As will be described in detail later, the pedestrian determination unit 16 determines whether or not the collision object is a pedestrian based on the calculation results of the load value calculation unit 12 and the duration calculation unit 14. Note that the determination by the pedestrian determination unit 16 is started, for example, when an ON signal is output from the touch sensor 34, and thereafter, is performed every calculation cycle by the load value calculation unit 12 and the duration calculation unit 14. Good.

  The control signal generator 18 generates a control signal according to the determination result of the pedestrian determination unit 16. For example, when the pedestrian determination unit 16 determines that the collision object is a pedestrian, the control signal generation unit 18 generates a control signal that activates the occupant protection device 20. Note that the control signal generation unit 18 may determine and adjust the activation timing and activation output of the occupant protection device 20 at activation as necessary.

  FIG. 4 shows test data in which the horizontal axis represents time (absolute time) and the vertical axis represents duration (duration by the duration calculation unit 14). FIG. 4 shows a plot line X when colliding with a heavy object (a weight approximately three times as large as an adult), a plot line Y1 when colliding with an adult (a dummy imitating an adult), and a 6-year-old child (6-year-old child). Plot line Y2 when colliding with a dummy) and plot line Z when a light-weight collision object collides with a shopping card (a shopping card with a weight equivalent to a 6-year-old child). . In addition, since the plot point when the light-weight collision object is a pylon is on the horizontal axis (the duration is substantially zero), the illustration is omitted from the viewpoint of clarity.

  As can be seen from FIG. 4, in the case of a light-weight collision object other than a pedestrian such as a shopping cart or a waste bin, the duration time is shorter than that of a pedestrian. Focusing on this point, in this embodiment, the lower limit threshold TH1 is set for the duration. In this case, the pedestrian determination unit 16 determines that the collision object is a pedestrian only when the duration of the duration calculation unit 14 exceeds the lower limit threshold TH1. Thereby, it is possible to prevent a light weight collision object other than a pedestrian such as a shopping cart or a waste bin from being determined as a pedestrian.

  In order to clarify the difference in duration between the pedestrian and the light-weight collision object as described above, the mounting position of the touch sensor 34 is preferably the upper part of the bumper (for example, the upper surface of the bumper reinforcement). ). This further facilitates the separation between a pedestrian who tends to ride on the vehicle body at the time of collision and a light-weight collision object (for example, a post cone or pylon) which tends to sink under the vehicle body at the time of collision. Moreover, you may reduce the sensitivity with respect to the vertical surface of the touch sensor 34. FIG. This further facilitates the separation between a pedestrian who tends to ride on the vehicle body at the time of a collision and a light-weight collision object (for example, a shopping cart or a waste bin) that often has a vertical end surface.

  A further preferred embodiment of the present invention will now be described with reference to FIGS.

  5 and 6 show a two-dimensional map used for determination by the pedestrian determination unit 16, FIG. 5 shows a two-dimensional map determined by the load applied to the vehicle from the outside and the duration, and FIG. 2 shows a two-dimensional map determined by an integral value of a load applied to the vehicle from the outside and a duration time.

  Each of the two-dimensional maps shown in FIG. 5 and FIG. 6 similarly includes a plot line X for a heavy object (a weight approximately three times as large as an adult) and a plot line Y1 for an adult (a dummy imitating an adult). , A plot line Y2 in the case of a 6-year-old child (a dummy imitating a 6-year-old child), and a plot line Z in the case where the light-weight collision object is a shopping card (weight equivalent to a 6-year-old child). In addition, since the plot point when the light-weight collision object is a pylon is on the horizontal axis (the duration is substantially zero), the illustration is omitted from the viewpoint of clarity.

  From FIG. 5 and FIG. 6, it is possible to separate a 6-year-old child (plot line Y2) and a light-weight collision object (plot line Z), which was conventionally difficult to be separated, by the lower threshold TH1 for the duration. I understand that In particular, in this embodiment, the plot line Y2 exceeds the lower threshold TH1 at least before the duration is maximized, that is, at least before the touch sensor 34 is turned off, and the 6-year-old child is separated from the light-weight collision object. Is possible. That is, according to the present embodiment, it is possible to reliably and quickly separate a 6-year-old child from a light-weight collision object. From this point of view, as shown in FIG. 7, the lower limit threshold TH1 for the map of FIG. 5 is smaller as the load applied to the vehicle from the outside (the load value calculated by the load value calculation unit 12) is larger. It ’s okay. Similarly, for the map of FIG. 6, the lower limit threshold TH1 has a large integrated value of the load applied to the vehicle from the outside (the integrated value of the load calculated by the load value calculating unit 12) as shown in FIG. A larger value may be taken.

  In the maps shown in FIGS. 5 and 6 and the like, an upper limit threshold TH2 is set for the duration time in order to exclude heavy objects from the determination target. Similarly, in order to improve judgment accuracy, the lower limit for the duration is limited only to the range of loads and load integral values that can be taken in the event of a collision with a 6-year-old child and an adult (the range between the lower threshold TH3 and the upper threshold TH4). A threshold value TH1 (and an upper threshold value TH2) is set.

  Next, with reference to FIG. 9, an operation example of the ECU 10 of the present embodiment using the map of FIG. 7 will be described. This routine is started when the touch sensor 34 is turned on.

  The load value calculation unit 12 calculates a load applied to the vehicle from the outside based on an output signal from the load sensor 32 input every predetermined cycle (step 100).

  The duration calculation unit 14 starts timing by a timer from when the touch sensor 34 is turned on, and calculates the duration (step 110).

  The pedestrian determination unit 16 determines that a plot point on the two-dimensional map determined by the load value obtained by the load value calculation unit 12 obtained in the current cycle and the duration time by the duration calculation unit 14 is a determination region G (see FIG. 7). It is judged whether it belongs to (step 120). When the plot point belongs to the determination region G, the pedestrian determination unit 16 determines that a collision with the pedestrian has occurred, and the control signal generation unit 18 activates the occupant protection device 20 (step 140). On the other hand, when the plot point does not belong to the determination region G, the predetermined end condition is satisfied in step 130 (for example, when the duration reaches the upper limit threshold TH2 or when the touch sensor 34 is turned off, When the time has elapsed), the processing from step 100 to step 120 is repeated.

  According to the present embodiment, the occupant protection device 20 is activated at a point α shown in FIG. 7 in the case of a collision with an adult and at a point β shown in FIG. 7 in the case of a collision with a 6-year-old child. It will be. However, the activation timing can be delayed if necessary according to the nature of the occupant protection device 20.

  In this embodiment, in order to eliminate the influence of noise or the like, it is possible to filter the load value and duration calculated by the load value calculator 12 and the duration calculator 14, or When the plot points belong to the determination region G continuously for a predetermined period, it may be determined that a collision with a pedestrian has occurred.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the present invention. Can be added.

  For example, in the above-described embodiment, when a plurality of load sensors 32 are set in the vehicle width direction (for example, a total of two on the left and right side members and / or a plurality of bumper reinforcements), May be used as the above-described “load applied to the vehicle from the outside”, and the integrated value of the total value may be used as “the integrated value of the load applied to the vehicle from the outside”. Alternatively, their average value may be used as well.

  In the embodiment described above, two or more touch sensors 34 may be set. In this case, considering that the pedestrian tends to ride on the vehicle body at the time of collision, a touch sensor having high sensitivity to the force from above the vehicle body may be used proactively or auxiliaryly.

It is a system configuration figure showing one example of a pedestrian collision judging device by the present invention. It is a bumper sectional view showing an example of mounting of load sensor 32 and touch sensor. It is a functional block diagram of ECU10 of a present Example. A graph is shown based on the test results with the horizontal axis representing time and the vertical axis representing duration. It is a figure which shows the relationship between the plot line based on a test result, and the determination area | region G by this invention (the 1). It is a figure which shows the relationship between the plot line based on a test result, and the determination area | region G by this invention (the 2). It is a figure which shows the relationship between the plot line based on a test result, and the determination area | region G by this invention (the 3). It is a figure which shows the relationship between the plot line based on a test result, and the determination area | region G by this invention (the 4). It is a flowchart which shows the operation example of ECU10 of a present Example.

Explanation of symbols

10 ECU
DESCRIPTION OF SYMBOLS 12 Load value calculation part 14 Duration time calculation part 16 Pedestrian determination part 18 Control signal generation part 20 Crew protection device 32 Load sensor 34 Touch sensor

Claims (5)

Load detecting means for detecting and outputting a load applied to the vehicle from outside, and a duration calculating means for calculating a duration of a state in which the load applied to the vehicle from outside exceeds a first predetermined value and does not fall below a second predetermined value; In the pedestrian collision determination device for determining whether the collision object is a pedestrian based on the output load of the load detection means and the duration time,
Load integral value for calculating the load integral value when the duration exceeds a lower limit threshold value, and the load integral value is calculated when the load detected by the load detection means exceeds a third predetermined value. A value calculating means,
A two-dimensional map in which a closed region defined by the lower and upper thresholds of the duration and the lower and upper thresholds of the load integral value is defined;
A pedestrian collision determination apparatus , wherein a collision object is determined to be a pedestrian when a point determined by the duration and the load integral value belongs to a closed region in the two-dimensional map . The pedestrian collision determination device according to claim 1 , wherein the lower limit threshold changes according to the load integral value. The pedestrian collision determination device according to claim 2 , wherein the lower limit threshold value increases as the load integral value increases.   The pedestrian collision determination device according to claim 1, wherein the duration calculation means calculates the duration based on an output state of an ON signal of a touch sensor mounted at a predetermined position of a vehicle body.   The pedestrian collision determination device according to claim 1, wherein the load detection unit includes a pressure sensor.

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