JP2015223956A - Collison detection system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a collision detection system which can accurately determine a failure during traveling even after a collision accident.SOLUTION: This collision detection system has: an X-axis sensor 41 which is smaller in a detection range than first acceleration sensors 11, 12, and detects acceleration in a vehicle fore-and-aft direction; a Y-axis sensor 42 which is smaller in a detection range than second acceleration sensors 21 to 24, and detects acceleration in a vehicle left-and-right direction; and a gyro sensor 44. The collision detection system also comprises a sensor set 4 which is arranged inside a vehicle rather than the first acceleration sensors 11, 12 and the second acceleration sensors 21 to 24, and further comprises a failure determination part 6 which determines the presence or absence of a failure on the basis of a comparison result between a detection value (yaw rate) of the gyro sensor 44 and a yaw rate calculation value which is calculated on the basis of detection values of the X-axis sensor 41 and the Y-axis sensor 42.

Description

  The present invention relates to a collision detection system that detects a collision of a vehicle.

  In general, a collision detection system (or occupant protection system) including an acceleration sensor or a gyro sensor that detects a collision has a configuration that diagnoses a failure based on an output of the sensor itself by a self-diagnosis function. In the collision detection system, as a primary diagnosis, a predetermined signal is applied to the diagnosis terminal of the sensor between when the ignition is turned on and the power is turned on until the operation is started, and based on an output signal corresponding to the signal. It is determined whether or not the sensor is abnormal. However, since the diagnosis signal and the actual detection value are difficult to distinguish while the vehicle is running, the primary diagnosis is not executed.

  In JP-A-2005-335501, the detection value of the angular velocity sensor that detects the roll angle, the detection value of the acceleration sensor in the vehicle left-right direction, and the detection value of the acceleration sensor in the vehicle vertical direction are compared with respective threshold values. A failure diagnosis device that determines a sensor failure based on a comparison result is described. As a result, the failure diagnosis device can diagnose the presence or absence of a failure related to the detection of the roll angle during traveling.

JP 2005-335501 A

  However, the failure diagnosis apparatus does not consider the influence on the acceleration sensor due to the collision of the vehicle, and has a problem in terms of failure determination accuracy.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a collision detection system that can accurately determine a failure during traveling even after a collision accident.

  In order to achieve the above object, a collision detection system according to aspect 1 of the present invention includes a first acceleration sensor (11, 12) that detects vehicle longitudinal acceleration and a second acceleration sensor that detects vehicle lateral acceleration. (21, 22, 23, 24), an X-axis sensor (41) for detecting acceleration in the longitudinal direction of the vehicle with a detection range smaller than that of the first acceleration sensor, and a detection range smaller than that of the second acceleration sensor. And at least two of a Y-axis sensor (42) for detecting the acceleration in the direction and a Z-axis sensor (43) for detecting the acceleration in the vehicle vertical direction, and at least one of the yaw rate, roll angle, and pitch angle in the vehicle. A gyro sensor (44) for detecting one of the sensors, and a sensor disposed on the inner side of the vehicle than the first acceleration sensor and the second acceleration sensor. A vehicle collision is determined based on the set (4, 40) and the detection value of the first acceleration sensor and the detection value of the X-axis sensor, or the detection value of the second acceleration sensor and the detection value of the Y-axis sensor. A collision determination unit (5) that performs detection when the detected value of the gyro sensor is a yaw rate, the detected value of the gyro sensor, the detected value of the X-axis sensor, and the Y-axis sensor. The yaw rate calculated value calculated based on the detected value of the sensor is compared, the presence or absence of a failure is determined based on the comparison result, and when the detected value of the gyro sensor is a roll angle, the detected value of the gyro sensor and The roll angle calculation value calculated based on the detection value of the Y-axis sensor and the detection value of the Z-axis sensor is compared, the presence or absence of a failure is determined based on the comparison result, and the gyro If the detected value of the sensor is a pitch angle, the detected value of the gyro sensor is compared with the calculated value of the pitch angle calculated based on the detected value of the X-axis sensor and the detected value of the Z-axis sensor. A failure determination unit (6) for determining the presence or absence of a failure based on the comparison result is provided.

  According to this configuration, the acceleration sensor that is disposed inside the vehicle and has a smaller detection range than the first acceleration sensor and the second acceleration sensor is used for failure determination. Thereby, the failure determination is executed based on a detection value that is not easily affected by a collision and has high detection accuracy. Therefore, according to the above-described aspect 1, accurate failure determination is performed even after a collision accident. Further, since the detection value of each sensor is used for failure determination, failure determination is possible even during traveling.

  The collision detection system according to aspect 2 of the present invention includes a first acceleration sensor (11, 12) that detects acceleration in the vehicle longitudinal direction and a second acceleration sensor (21, 22, 23, that detects acceleration in the vehicle lateral direction). 24), an X-axis sensor (41) for detecting acceleration in the vehicle longitudinal direction with a detection range smaller than that of the first acceleration sensor, and a Y for detecting acceleration in the vehicle lateral direction with a detection range smaller than that of the second acceleration sensor. A sensor set (4, 40) having an axis sensor (42) and a yaw sensor (441) for detecting a yaw rate in the vehicle, and disposed on the vehicle inner side than the first acceleration sensor and the second acceleration sensor; Based on the detection value of the first acceleration sensor and the detection value of the X-axis sensor, or the detection value of the second acceleration sensor and the detection value of the Y-axis sensor A collision detection system that determines a collision of the yaw sensor, and is calculated based on a detection value of the yaw sensor, a detection value of the X-axis sensor, and a detection value of the Y-axis sensor A failure determination unit (6) that compares the yaw rate calculation value and determines the presence or absence of failure based on the comparison result is provided. Even with this configuration, the same effect as in the first aspect is exhibited. In addition, the code | symbol in the bracket | parenthesis of each means described in this column and the claim shows the correspondence with the specific means as described in embodiment mentioned later.

It is a block diagram which shows the structure of the collision detection system of 1st embodiment. It is a block diagram which shows the structure of ECU of 1st embodiment. It is explanatory drawing for demonstrating the calculation of the failure determination part of 1st embodiment. It is explanatory drawing for demonstrating the failure determination of 1st embodiment. It is a flowchart for demonstrating the failure determination of 1st embodiment. It is a block diagram which shows the structure of the sensor set of 2nd embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, the same or equivalent parts are denoted by the same reference numerals in the drawings. Each figure used for explanation is a conceptual diagram, and the shape of each part may not necessarily be exact.

<First embodiment>
As shown in FIG. 1, the collision detection system of the first embodiment includes front sensors (corresponding to “first acceleration sensor”) 11 and 12, side sensors (corresponding to “second acceleration sensor”) 21, 22, 23, 24 and ECU3.

  The front sensors 11 and 12 are so-called G sensors, and are acceleration sensors that detect acceleration in the vehicle longitudinal direction. The front sensor 11 is disposed on the right side of the vehicle in a front part of the vehicle (for example, in the front bumper). The front sensor 12 is disposed on the left side of the vehicle in a front part of the vehicle (for example, in the front bumper). The detection range (detectable range) of the front sensors 11 and 12 of this embodiment is one hundred to several hundreds G. The front sensors 11 and 12 transmit a detection signal (detection value) to the ECU 3.

  The side sensors 21 to 24 are so-called G sensors, and are acceleration sensors that detect acceleration in the lateral direction of the vehicle. The side sensor 21 is disposed in a front part on the right side of the vehicle (for example, in the door on the right side of the front seat or in the B pillar). The side sensor 22 is disposed in a rear part on the right side of the vehicle (for example, in the door on the right side of the rear seat or above the tire house). The side sensor 23 is disposed in a front part on the left side of the vehicle (for example, in the door on the left side of the front seat or in the B pillar). The side sensor 24 is disposed at a rear portion on the left side of the vehicle (for example, in the door on the left side of the rear seat or above the tire house). The detection range of the side sensors 21 to 24 is one hundred to several hundreds G. The side sensors 21 to 24 transmit detection signals (detection values) to the ECU 3. In the present specification, the front sensors 11 and 12 and the side sensors 21 to 24 are also collectively referred to as “acceleration sensors 11, 12, and 21 to 24”.

  The ECU 3 is an electronic control unit that includes a CPU and a memory. ECU3 is arrange | positioned in the center part (for example, between the right and left seats of a front row, such as a center console) in the vehicle interior A. As shown in FIG. 2, the ECU 3 includes a reception unit 31, a recording unit 32, a transmission unit 33, a sensor set 4, a collision determination unit 5, and a failure determination unit 6.

  The receiving unit 31 is an interface, receives detection signals from the acceleration sensors 11, 12, and 21 to 24 and transmits them to the collision determination unit 5 and the failure determination unit 6. The recording unit 32 is a memory and records the determination results of the collision determination unit 5 and the failure determination unit 6. The transmission unit 33 is an interface, and transmits the determination results of the collision determination unit 5 and the failure determination unit 6 to an external device (occupant protection ECU, a failure notification device such as a warning light).

  The sensor set 4 is a member in which a plurality of sensors are arranged on a substrate. The sensor set 4 includes an X-axis sensor 41, a Y-axis sensor 42, a Z-axis sensor 43, and a gyro sensor 44, each alone or as a combo of a plurality of elements.

  The X-axis sensor 41 is a so-called G sensor, and is an acceleration sensor that detects acceleration in the vehicle longitudinal direction. The detection range of the X-axis sensor 41 is smaller than the detection ranges of the front sensors 11 and 12. The detection range of the X-axis sensor 41 of this embodiment is several G to several tens of G. The Y-axis sensor 42 is a so-called G sensor, and is an acceleration sensor that detects acceleration in the left-right direction of the vehicle. The detection range of the Y-axis sensor 42 is smaller than the detection ranges of the side sensors 21 to 24. The detection range of the Y-axis sensor 42 of this embodiment is several G to several tens of G. The Z-axis sensor 43 is a so-called G sensor, and is an acceleration sensor that detects acceleration in the vehicle vertical direction. The detection range of the Z-axis sensor 43 of this embodiment is several G to several tens of G.

  The resolution of the detection signal is the same for all acceleration sensors. Therefore, the smaller the detection range, the better the detection accuracy in that range. Further, the change in acceleration (G) due to the collision is attenuated to about 1/10 with respect to the outer surface side when transmitted to the ECU 3. In this specification, the X-axis sensor 41, the Y-axis sensor 42, and the Z-axis sensor 43 are also collectively referred to as “acceleration sensors 41 to 43”.

  The gyro sensor 44 includes a yaw sensor 441, a roll sensor 442, and a pitch sensor 443. The yaw sensor 441 is a sensor that detects an angular velocity of rotation about the Z axis (the vehicle vertical direction), that is, a yaw rate. The roll sensor 442 is a sensor that detects a rotation angle with the X axis (vehicle longitudinal direction) as a rotation axis, that is, a roll angle. The pitch sensor 443 is a sensor that detects a rotation angle with the Y axis (the vehicle left-right direction) as a rotation axis, that is, a pitch angle.

  The collision determination unit 5 determines the presence or absence of a collision in the vehicle front-rear direction based on the detection values of the front sensors 11 and 12 and the detection value of the X-axis sensor 41. In the collision determination unit 5, a first front / rear threshold, a second front / rear threshold, a first left / right threshold, and a second left / right threshold are recorded. When the detection value of at least one of the two front sensors 11 and 12 exceeds the first front-rear threshold value and the detection value of the X-axis sensor 41 exceeds the second front-rear threshold value, the collision determination unit 5 It is determined that there is a collision. Further, the collision determination unit 5 determines the presence or absence of a collision in the vehicle left-right direction based on the detection values of the side sensors 21 to 24 and the detection value of the Y-axis sensor 42. When at least one detection value of the side sensors 21 to 24 exceeds the first left-right threshold value and the detection value of the Y-axis sensor 42 exceeds the second left-right threshold value, the collision determination unit 5 It is determined as “Yes”. The acceleration sensors 41 to 43 are safing sensors. The ECU 3 may determine an airbag to be deployed according to the yaw rate of the yaw sensor 441 among the plurality of airbags.

  The failure determination unit 6 performs failure determination in response to reception of detection signals from the sensor set 4 and the gyro sensor 44. Specifically, the failure determination unit 6 calculates a yaw rate calculation value based on the detection value of the X-axis sensor 41 and the detection value of the Y-axis sensor 42. The failure determination unit 6 calculates a roll angle calculation value based on the detection value of the Y-axis sensor 42 and the detection value of the Z-axis sensor 43. The failure determination unit 6 calculates a pitch angle calculation value based on the detection value of the X-axis sensor 41 and the detection value of the Z-axis sensor 43.

  The calculation of the failure determination unit 6 converts a calculation value that can be compared with a detection value to be compared. As for the yaw rate calculation value θy, for example, as shown in FIG. 3, first, the calculation angle θ1 (calculation formula θ1) at the time t from the detection value x1 of the X-axis sensor 41 and the detection value y1 of the Y-axis sensor 42 at the time t. = Arctan (x1 / y1)) is calculated. Then, from the detection value x2 of the X-axis sensor 41 and the detection value y2 of the Y-axis sensor 42 at time t + Δt, the calculation angle θ2 (calculation formula θ2 = arctan (x2 / y2)) at time t + Δt is calculated. From the calculation angle θ1, the calculation angle θ2, and the time Δt, a yaw rate calculation value θy (calculation formula θy = (θ1−θ2) / Δt) that is an angular velocity is calculated. The yaw rate calculation value θy corresponds to the detection value of the yaw sensor 441.

  The roll angle calculation value θr is obtained from the detection value y1 of the Y-axis sensor 42 and the detection value z1 of the Z-axis sensor 43 at time t, and the detection value y2 of the Y-axis sensor 42 and detection value z2 of the Z-axis sensor 43 at time t + Δt. Calculated. The roll angle calculation value θr can be calculated by, for example, the calculation formula θr = (arctan (z1 / y1) −arctan (z2 / y2)) / Δt. The roll angle calculation value θr corresponds to the detection value of the roll sensor 442.

  The calculated pitch angle value θp is based on the detected value x1 of the X-axis sensor 41 and the detected value z1 of the Z-axis sensor 43 at time t, and the detected value x2 of the X-axis sensor 41 and detected value z2 of the Z-axis sensor 43 at time t + Δt. Calculated. The pitch angle calculation value θp can be calculated by, for example, the calculation formula θp = (arctan (z1 / x1) −arctan (z2 / x2)) / Δt. The pitch angle calculation value θp corresponds to the detection value of the pitch sensor 443.

  As shown in FIG. 4, the failure determination unit 6 compares the yaw rate calculation value with the detection value of the yaw sensor 441 and determines the presence or absence of a failure based on the comparison result. Specifically, when the deviation between the yaw rate calculation value and the detection value of the yaw sensor 441 exceeds a predetermined value, the failure determination unit 6 determines that at least one of the X-axis sensor 41, the Y-axis sensor 42, and the yaw sensor 441 is Determine that there is a failure. Similarly, the failure determination unit 6 compares the roll angle calculation value with the detection value of the roll sensor 442. If the deviation between the two exceeds a predetermined value, the Y-axis sensor 42, the Z-axis sensor 43, and the roll sensor 442 It is determined that at least one of them has failed. Similarly, the failure determination unit 6 compares the pitch angle calculation value with the detection value of the pitch sensor 443, and if the deviation between the two exceeds a predetermined value, the X-axis sensor 41, the Z-axis sensor 43, and the pitch sensor 443. It is determined that at least one of them has failed.

  The failure determination unit 6 performs the failure determination (always diagnosis) during traveling after the primary diagnosis based on the diagnosis signal. As shown in FIG. 4, even if the diagnosis signal is a normal value in the primary diagnosis, the failure determination unit 6 has a case where the deviation between the detected value and the calculated value is outside the normal range (predetermined value) in the normal diagnosis. It is determined that there is a failure. The failure determination unit 6 can determine that there is a failure before the detected value reaches the upper limit value.

  The control flow of the first embodiment will be described by taking the yaw rate as an example. As shown in FIG. 5, the failure determination unit 6 acquires detection values from the X-axis sensor 41 and the Y-axis sensor 42 at time t1 (S101). Subsequently, the failure determination unit 6 acquires detection values from the X-axis sensor 41 and the Y-axis sensor 42 at time t2 (t1 + Δt) (S102). The failure determination unit 6 calculates a yaw rate calculation value from the acquired detection value (S103). The failure determination unit 6 compares the yaw rate calculation value with the detection value of the yaw sensor 441 at time t2, and determines whether or not the deviation between the two is less than or equal to a predetermined value (S104). When the deviation is equal to or smaller than the predetermined value (S104: Yes), the failure determination unit 6 determines “normal” (S105). When the deviation is not less than the predetermined value (S104: No), the failure determination unit 6 determines “failure (abnormal)” (S106). Similarly, in the case of the roll angle and the pitch angle, the calculated value and the detected value at the time corresponding to each other are compared.

  According to the collision detection system of the first embodiment, the acceleration sensors 11, 12, 21 to 24 are disposed on the outer surface side of the vehicle, whereas the acceleration sensors 41 to 43 are disposed on the vehicle inner side. . As a result, the acceleration sensors 11, 12, 21 to 24 require high impact resistance, but the acceleration sensors 41 to 43 have lower impact resistance sensors than the acceleration sensors 11, 12, 21 to 24. Applicable. That is, an acceleration sensor having a detection range smaller than that of the acceleration sensors 11, 12, 21 to 24 can be used for the acceleration sensors 41 to 43. The acceleration sensors 11, 12, 21 to 24 can detect a collision directly and early on the outer surface side of the vehicle. On the other hand, the acceleration sensors 41 to 43 have high sensitivity, quantization error, and the like. It is possible to arrange an acceleration sensor with a small amount. Therefore, the acceleration sensors 41 to 43 can be used as a failure determination or a safing sensor. That is, the failure determination unit 6 performs failure determination based on the detected values of the acceleration sensors 41 to 43 that are physically less susceptible to the influence of the collision and have high accuracy. Can do.

  Further, since the detected values during traveling of the acceleration sensors 41 to 43 and the gyro sensor 44 are used, it is possible to determine a failure even during traveling. Further, since a threshold is set for the deviation (difference) between the calculated value and the detected value, it is detected that there is a failure before the detected value of the acceleration sensors 41 to 43 or the gyro sensor 44 reaches the upper limit value. The The failure determination unit 6 can detect a failure early during traveling.

  Further, since the acceleration sensors 41 to 43 and the gyro sensor 44 are arranged at positions close to each other (on the same substrate in the present embodiment), the failure determination accuracy based on the detected values of both is high. Further, according to the first embodiment, failure determination can be performed for any detection value (yaw rate, roll angle, and pitch angle) of the gyro sensor 44.

<Second embodiment>
The collision detection system of the second embodiment is different from the first embodiment in that the Z-axis sensor 43, the roll sensor 442, and the pitch sensor 443 are not provided. Therefore, a different part is demonstrated. The same reference numerals as those in the first embodiment indicate the same configurations as those in the first embodiment, and the preceding description is referred to.

  As shown in FIG. 6, the sensor set 40 of the second embodiment includes an X-axis sensor 41, a Y-axis sensor 42, and a yaw sensor 441. As in the first embodiment, the failure determination unit 6 compares the yaw rate calculation value based on the detection value of the X-axis sensor 41 and the detection value of the Y-axis sensor 42 with the detection value of the yaw sensor 441, and the deviation between both is a predetermined value. If it exceeds, it is determined as a failure. The collision determination unit 5 determines a collision as in the first embodiment. The effect similar to 1st embodiment is exhibited also by 2nd embodiment.

<Others>
The present invention is not limited to the above embodiment. The gyro sensor 44 only needs to detect at least one of the yaw rate, roll angle, and pitch angle. The sensor set 4 includes not all of the acceleration sensors 41 to 43 but two sensors corresponding to the detection elements of the acceleration sensors 41 to 43 corresponding to the detection elements of the gyro sensor 44 or to perform failure determination. May be. The gyro sensor 44 is not limited to collision detection and occupant protection, and may be arranged for the purpose of improving passenger comfort. Moreover, the calculation which the failure determination part 6 performs is not restricted above. For example, the detection value of the gyro sensor 44 may be decomposed into axial components (X axis, Y axis, or Z axis) and compared with the detection values of the corresponding acceleration sensors 41 to 43. In this case, the component value decomposed into the axis components corresponds to the calculated value. Further, differentiation or integration may be used for the calculation.

  The present invention is not limited to the case where the ECU 3 is used, and the sensor sets 4 and 40 may be arranged separately from the arithmetic device (the collision determination unit 5 or the failure determination unit 6). For example, the sensor sets 4 and 40 may be arranged in the central part (for example, in the center console) in the passenger compartment A, and the arithmetic unit having a CPU may be arranged in the front part (for example, in the dashboard) in the passenger compartment A. . Moreover, each sensor of the sensor sets 4 and 40 may not be arranged on one substrate (on the same substrate).

  Further, the resolution of the detection signal may not be the same for all acceleration sensors. For example, the resolution of the front sensors 11 and 12 may be 256, the resolution of the side sensors 21 to 24 may be 256, and the resolution of the X-axis sensor 41, the Y-axis sensor 42, the Z-axis sensor 43, and the gyro sensor 44 may be 512.

11, 12: Front sensor (first acceleration sensor),
21, 22, 23, 24: side sensor (second acceleration sensor),
3: ECU, 4, 40: sensor set, 41: X-axis sensor,
42: Y-axis sensor, 43: Z-axis sensor, 44: Gyro sensor,
441: Yaw sensor, 442: Roll sensor, 443: Pitch sensor,
5: Collision determination unit, 6: Failure determination unit, A: Vehicle compartment

Claims (3)

A first acceleration sensor (11, 12) for detecting acceleration in the vehicle longitudinal direction;
A second acceleration sensor (21, 22, 23, 24) for detecting acceleration in the vehicle lateral direction;
An X-axis sensor (41) that detects acceleration in the vehicle longitudinal direction with a detection range smaller than that of the first acceleration sensor, and a Y-axis sensor (42) that detects acceleration in the vehicle lateral direction with a detection range smaller than that of the second acceleration sensor. ) And at least two of the Z-axis sensors (43) for detecting acceleration in the vertical direction of the vehicle, and a gyro sensor (44) for detecting at least one of the yaw rate, roll angle and pitch angle in the vehicle. And a sensor set (4, 40) disposed on the vehicle inner side than the first acceleration sensor and the second acceleration sensor;
A collision determination unit (5) for determining a vehicle collision based on the detection value of the first acceleration sensor and the detection value of the X-axis sensor, or the detection value of the second acceleration sensor and the detection value of the Y-axis sensor; ,
A collision detection system comprising:
When the detected value of the gyro sensor is a yaw rate, the detected value of the gyro sensor is compared with the detected value of the X axis sensor and the calculated yaw rate based on the detected value of the Y axis sensor, and Determine the presence or absence of failure based on the comparison results,
When the detected value of the gyro sensor is a roll angle, the detected value of the gyro sensor is compared with the calculated roll angle value based on the detected value of the Y-axis sensor and the detected value of the Z-axis sensor. , Determine the presence or absence of failure based on the comparison result,
When the detected value of the gyro sensor is a pitch angle, the detected value of the gyro sensor is compared with the calculated value of the pitch angle calculated based on the detected value of the X-axis sensor and the detected value of the Z-axis sensor. A collision detection system comprising a failure determination unit (6) for determining the presence or absence of a failure based on the comparison result. A first acceleration sensor (11, 12) for detecting acceleration in the vehicle longitudinal direction;
A second acceleration sensor (21, 22, 23, 24) for detecting acceleration in the vehicle lateral direction;
An X-axis sensor (41) that detects acceleration in the vehicle longitudinal direction with a detection range smaller than that of the first acceleration sensor, and a Y-axis sensor (42) that detects acceleration in the vehicle lateral direction with a detection range smaller than that of the second acceleration sensor. ), And a sensor set (4, 40) having a yaw sensor (441) for detecting a yaw rate in the vehicle, and disposed on the vehicle inner side than the first acceleration sensor and the second acceleration sensor,
A collision determination unit (5) for determining a vehicle collision based on the detection value of the first acceleration sensor and the detection value of the X-axis sensor, or the detection value of the second acceleration sensor and the detection value of the Y-axis sensor; ,
A collision detection system comprising:
A failure determination that compares the detected value of the yaw sensor with the calculated yaw rate based on the detected value of the X-axis sensor and the detected value of the Y-axis sensor, and determines the presence or absence of a failure based on the comparison result A collision detection system comprising a section (6).   The collision detection system according to claim 1 or 2, wherein the sensor set is disposed in a passenger compartment (A).

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