JP2018149827A - Occupant impact mitigation apparatus and occupant impact mitigation program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an occupant impact mitigation apparatus and an occupant impact mitigation program capable of effectively mitigating an impact to an occupant while securing a space for protecting an occupant when a collision occurs.SOLUTION: A relative distance and a relative speed with respect to an object are detected (100) by acquiring a detection result of a radar sensor 14, and a collision time with an object and a relative speed at a time of collision are estimated based on the relative distance and the relative speed (102). In addition, a passenger target deceleration at a time of a collision is set (106) using a predetermined model for obtaining an occupant target deceleration at a time of a collision from a collision time and a relative speed at a time of collision. Then, based on an occupant deceleration and a time from a current time to a time of collision, a seat control force and a start time of a seat movement control are obtained (108), and driving of a seat drive actuator is started when a start time comes (112, 114).SELECTED DRAWING: Figure 6

Description

  The present invention relates to an occupant impact mitigation device and an occupant impact mitigation program for mitigating an impact generated on an occupant during a collision.

  Conventionally, various technologies for protecting an occupant by absorbing an impact on the occupant when a vehicle collides have been proposed (for example, Patent Documents 1 and 2).

  In the technique described in Patent Document 1, the collision and the collision direction of the vehicle are detected in advance, and when the collision is detected in advance, the movement direction and the movement amount with respect to the sheet are determined according to the collision direction, and the sheet is It has been proposed to drive. This makes it possible to secure a collision-response space that can avoid damage to the passenger body due to deformation of the passenger compartment in advance.

  Further, in the technique described in Patent Document 2, it is proposed to detect a vehicle collision and drive the seat when the collision is detected, and the seat deceleration is driven to a predetermined pattern. Thus, the deceleration applied to the occupant can be reduced.

JP 2006-44409 A JP 2006-56440 A

  However, in Patent Document 1, for the purpose of securing a collision response space that can avoid an occupant's obstacle, the collision is predicted in advance and the movement direction and movement amount of the seat are determined to drive the seat. There is room for improvement because it does not consider mitigating the impact on passengers.

  In Patent Document 2, the deceleration applied to the occupant is reduced by moving the seat backward after the collision. However, since the seat is moved after the collision, the seat is moved after the deceleration due to the collision is applied to the occupant. Since it moves, there is room for improvement in order to reduce the impact on the passenger.

  The present invention has been made in consideration of the above facts, and has a passenger impact mitigation device and an occupant impact capable of effectively mitigating an impact on the occupant while ensuring a space for protecting the occupant when a collision occurs. The purpose is to provide mitigation programs.

  In order to achieve the above object, an occupant impact mitigation device according to the present invention includes a drive unit that drives a vehicle seat to the rear of the vehicle, a relative distance between the collision target, a relative speed with the collision target, and a relative relationship with the collision target. A detection unit that detects acceleration or each of the relative distance and the relative velocity; an estimation unit that estimates a time to collision and a relative velocity at the time of collision based on a detection result of the detection unit; and the collision When the time until the time is within a predetermined time, the target deceleration determined based on the estimation result of the estimation unit starts driving the seat to the rear of the vehicle at the driving start timing generated in the seat at the time of collision. And a control unit for controlling the drive unit.

  According to the occupant impact mitigation device according to the present invention, the vehicle seat is driven rearward by the drive unit.

  The detection unit detects the relative distance to the collision target, the relative speed to the collision target, and the relative acceleration to the collision target, or each of the relative distance and the relative speed.

  Further, the estimation unit estimates each of the time until the collision and the relative speed at the time of the collision based on the detection result of the detection unit.

  Then, in the control unit, when the time until the collision is within a predetermined time, the target deceleration determined based on the estimation result of the estimation unit is driven to the rear of the vehicle at the driving start timing generated in the seat at the time of the collision. The drive unit is controlled to start driving. That is, the driving of the sheet is started before the collision occurs, and the sheet is driven so that the target deceleration is generated on the sheet when the collision occurs. Thereby, the impact applied to the occupant at the time of the collision can be reduced as compared with the conventional method of reducing the impact by driving the seat after the collision occurs. Further, with respect to the movement of the occupant and the seat with respect to the collision target, it is possible to secure a space for protecting the occupant when the collision occurs by suppressing the amount of movement of the occupant as compared with the conventional method of reducing the impact by driving the seat after the collision occurs. Therefore, it is possible to effectively reduce the impact on the occupant while securing a space for protecting the occupant when a collision occurs.

  Further, as in the invention described in claim 2, the control unit sets a target deceleration from the estimation result of the estimation unit using a predetermined model, and sets the target deceleration set by the setting unit. A determination unit that determines each of the driving force of the generated driving unit and the driving start timing of the seat that is generated when the target deceleration occurs at the time of collision, and the driving unit may be controlled based on the determination result of the determination unit . Thereby, the target deceleration can be set from the estimated time to the collision and the relative speed at the time of the collision, the driving force of the driving unit and the seat start timing can be determined, and the driving unit can be controlled.

  In addition, as in the third aspect of the invention, a detection unit that detects a collision may further be provided, and the control unit may sequentially update the driving force and the drive start timing until the detection unit detects a collision. Thereby, the estimation error can be corrected up to the moment of the collision, and the control accuracy can be improved.

  In the present invention, as in the invention described in claim 4, occupant impact mitigation for causing a computer to function as the detection unit and control unit of the occupant impact mitigation device described in any one of claims 1 to 3. It may be a program.

  As described above, according to the present invention, there is an effect that it is possible to provide an occupant impact mitigation device capable of effectively mitigating an impact on the occupant while securing a space for protecting the occupant when a collision occurs. .

1 is a block diagram illustrating a schematic configuration of an occupant impact mitigation device according to the present embodiment. It is a figure which shows the movement of the sheet | seat by a sheet drive actuator. (A) is a figure which shows the deceleration of the seat | sheet in the case of the model assumed that a passenger | crew and a seat move integrally, (B) is a figure which shows the seat control force in the case of (A), (C () Is a diagram for explaining the determination of the sheet movement start time in the case of (A). (A) is a figure which shows the deceleration of the seat | sheet in the case of the model which considers even the behavior of a seatbelt and a passenger | crew, (B) is a figure which shows the seat control force in the case of (A), (C) is It is a figure for demonstrating determination of the sheet | seat movement start time in the case of (A). (A) is a figure for demonstrating the model which considers even the behavior of a seatbelt and a passenger | crew, (B) is a figure which shows the example which calculates | requires a seat target deceleration using a map from relative speed and the time to a collision. is there. It is a flowchart which shows an example of the flow of the impact relaxation sheet | seat control performed by passenger | crew impact mitigation ECU of the passenger | crew impact mitigation apparatus which concerns on this embodiment. (A) is a figure which shows the example of the waveform of the passenger | crew deceleration obtained by the high-speed full lap collision test simulation in the conventional method, (B) is the waveform of the passenger | crew deceleration obtained by the high-speed full lap collision test simulation in this embodiment. It is a figure which shows an example, (C) is a figure which shows the example of a waveform of the passenger | crew and seat displacement with respect to the collision object obtained by the high-speed full wrap collision test simulation in a conventional method, (D) is the high-speed full wrap in this embodiment. It is a figure which shows the example of a waveform of the displacement of the passenger | crew and the sheet | seat 20 with respect to the collision target obtained by the collision test simulation.

  Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing a schematic configuration of an occupant impact mitigation device according to the present embodiment.

  As shown in FIG. 1, an occupant impact mitigation device 10 according to this embodiment includes an occupant impact mitigation ECU (Electronic Control Unit) 12. The occupant impact mitigation ECU 12 includes a computer in which a CPU 12A, a ROM 12B, a RAM 12C, and an I / O (input / output interface) 12D are connected to a bus 12E. The passenger impact mitigation ECU 12 corresponds to an estimation unit and a control unit.

  The ROM 12B stores a program for performing impact mitigation seat control (details will be described later) for controlling the seat to mitigate the impact on the passenger due to the collision. The program stored in the ROM 12B is expanded on the RAM 12C and executed by the CPU 12A, whereby the impact mitigating sheet control is performed.

  The I / O 12D is connected to a radar sensor 14, a collision detection sensor 16, and a sheet drive actuator 18 as an example of a drive unit.

  The radar sensor 14 transmits a signal for detecting a relative distance and a relative speed with an object such as a vehicle around the vehicle, receives a signal reflected by the object, and outputs a reception result to the occupant impact mitigation ECU 12. To do. For example, an ultrasonic radar, a millimeter wave radar, or the like is applied to the radar sensor 14, and the occupant impact mitigation ECU 12 detects a relative distance from an object around the vehicle based on a signal from the radar sensor 14, and the relative distance time is determined. The relative speed is detected from the change. In the present embodiment, the relative distance and the relative speed are detected based on the detection result of the radar sensor 14, but the present invention is not limited to this. For example, the occupant can determine the relative distance and relative speed of the object based on a signal from an imaging device such as a camera or a stereo camera, or a rider for detecting an object around the vehicle by irradiating a laser beam or the like. The impact mitigation ECU 12 may detect it. In the present embodiment, the radar sensor 14 and the passenger impact mitigation ECU 12 correspond to an example of a detection unit.

  The collision detection sensor 16 detects a physical quantity for detecting the occurrence of a collision. For example, the occurrence of a collision is detected by detecting acceleration as a physical quantity generated by the collision and outputting the detection result to the occupant impact relaxation ECU 12. When detecting the acceleration, the collision detection sensor 16 detects, for example, an acceleration in the front-rear direction of the vehicle or an acceleration in the vehicle width direction. The collision detection sensor 16 may detect a physical quantity other than acceleration. For example, the detection result of a strain sensor or the like may be detected as a physical quantity. In the present embodiment, the collision detection sensor 16 and the occupant impact relaxation ECU 12 correspond to an example of a detection unit.

  As shown in FIG. 2, the seat drive actuator 18 slides the vehicle seat 20 rearward (in the direction of the arrow in FIG. 2). In the present embodiment, the seat driving actuator is driven in accordance with the timing of the occurrence of the collision before the collision occurs, and the seat 20 is moved rearward of the vehicle to reduce the impact on the occupant. As the drive source, for example, various known drive sources such as hydraulic pressure, electricity, and explosive can be applied. As long as the seat drive actuator 18 can drive the occupant and the seat 20 with a predetermined weight and responsiveness, any drive source may be applied.

  Here, the above-described impact relaxation seat control performed by the occupant impact relaxation ECU 12 will be described.

  In the present embodiment, the occupant impact mitigation ECU 12 acquires the detection result of the radar sensor 14 to detect the relative distance Δx (t) and the relative speed Δv (t) with the object.

  Further, the occupant impact relaxation ECU 12 estimates the collision time t_end with the object and the relative speed Δv (t_end) at the time of the collision based on the detected relative distance Δx (t) and relative speed Δv (t). Although it is preferable to detect the relative deceleration ΔG (t) and estimate the time t_end at the time of collision and the relative velocity Δv (t_end) at the time of the collision, in this embodiment, the relative deceleration ΔG (t) is The description will be made assuming 0.

  Then, the occupant target deceleration G_target at the time of collision is set using a predetermined model for obtaining the occupant target deceleration G_target at the time of collision from the collision time t_end and the relative speed Δv (t_end) at the time of collision. The requirements for determining the occupant target deceleration G_target are that the maximum deceleration after the collision does not exceed a predetermined maximum value (maximum occupant deceleration) and the amount of displacement at which the vehicle collapses after the collision The calculation is performed based on a predetermined model in consideration of a point that does not exceed the space for securing (impact mitigation space securing). This calculation depends on the compliance characteristics of the vehicle. The compliance characteristic is a physical quantity indicating the ease of deformation of an object, and is determined by the rigidity of the side member of the vehicle. As a method for determining the compliance characteristics, for example, the method described in Koji Mizuno, “Automobile Collision Safety”, Nagoya University Press, 2012 can be applied.

  Further, the occupant impact mitigation ECU 12 obtains the seat control force and the drive start timing of the seat 20 based on the obtained occupant target deceleration G_target and the time Δt = t_end-t (current time) from the current time to the collision. The seat control force obtains the driving force of the seat driving actuator 18 that generates the occupant target deceleration G_target when the rearward movable amount (maximum displacement) of the seat 20 is moved during the time Δt until the collision. Further, as the drive start timing, the start time t_start of the sheet movement control is obtained by using the target deceleration G_target as the drive start timing of the seat 20 generated at the time of the collision.

  In addition, the processing up to now is sequentially performed to update the seat control force and the start time t_start of the seat movement control, and the estimation error is corrected to the moment of the collision to improve the control accuracy. Then, at the start time t_start, the driving of the sheet driving actuator 18 is started. Although various control patterns of the sheet drive actuator can be considered, here, in order to simplify the description, it is assumed that a constant force is applied to the seat 20. In addition, the sheet control force and the start time t_start of the sheet movement control are updated even after the driving of the sheet is started. After the driving of the sheet is started, the sheet control force and the movement of the sheet are taken into consideration in consideration of the displaceable amount of the remaining sheets. Update the control start time.

  The start time t_start of the seat movement control can be easily calculated in the case of a model that assumes that the occupant and the seat 20 move together without considering the characteristics (rigidity, play, etc.) of the seat belt. For example, as shown in FIG. 3B, assuming that the sheet control force is constant, the start time t_start of the sheet movement control is obtained when the area of the triangle and the slope of the hypotenuse of the hatched portion in FIG. 3C are determined. Can do. That is, when the seat control force is a constant value, the inclination of the hypotenuse of the triangle corresponds to the deceleration of the seat 20, and therefore, if the occupant target deceleration G_target shown in FIG. . Further, since the triangular area in FIG. 3C corresponds to the movement amount of the seat 20, the maximum displacement that can move the movement amount to the vehicle rear side of the seat 20 is the area. Therefore, the control start time t_start can be calculated from these.

  On the other hand, as shown in FIG. 4A, in the case of a model that takes into account the behavior of the seat belt and the occupant, a delay occurs in the displacement of the occupant with respect to the seat control. It is necessary to predict the passenger deceleration at the time of collision. Specifically, the seat control is performed so that the area of the triangle indicated by hatching in FIG. In this control, the constraint condition is that the seat control force does not exceed the upper limit. The solid line in FIG. 4A indicates the seat deceleration, and the alternate long and short dash line indicates the occupant deceleration, but the occupant deceleration rises with respect to the rise of the seat deceleration, so the model assuming the seat belt as a spring model, etc. Is used to find the occupant target deceleration. Further, a target deceleration G_target of the seat 20 that is the determined occupant target deceleration is obtained.

  In the case of a model that takes into account the behavior of the seat belt and the occupant, for example, as shown in FIG. 5A, the seat control before the collision and the seat belt rigidity are modeled, and the vehicle body rigidity after the collision is modeled. Is modeled. Then, the target deceleration G_target of the seat 20 is directly obtained by performing forward calculation using the respective models with the time to collision Δt = t_end-t and the estimated relative velocity Δv (t_end) at the time of collision as input values. Further, when modeling, as described above, modeling is performed with the occupant maximum deceleration and the impact mitigation space secured as constraints, and the time to collision Δt = t_end-t and the relative velocity Δv (t_end) at the time of collision The target deceleration G_target of the seat 20 is directly obtained.

  Further, when the target deceleration of the seat 20 is obtained, it may be calculated online in real time by a model predictive control method or the like. Alternatively, using a model, as shown in FIG. 5 (B), a map 22 is prepared in advance to obtain the seat target deceleration G_target for the time Δt = t_end-t until the collision and the relative speed Δv (t_end) at the time of the collision. The seat target deceleration G_target may be sequentially updated using the map 22 during the control by the occupant impact relaxation ECU 12.

  Next, a specific flow of impact mitigating seat control performed by the occupant impact mitigating ECU 12 of the occupant impact mitigating device 10 according to the present embodiment configured as described above will be described. FIG. 6 is a flowchart showing an example of the flow of impact mitigating seat control performed by the occupant impact mitigating ECU 12 of the occupant impact mitigating device 10 according to the present embodiment. Note that the processing in FIG. 6 starts when, for example, an ignition switch (not shown) is turned on or when the start of traveling of the vehicle is detected.

  In step 100, the CPU 12A detects the relative distance Δx (t) and the relative speed Δv (t) at the current time, and proceeds to step 102. That is, the CPU 12A acquires the detection result of the radar sensor 14, thereby detecting the relative distance Δx (t) and the relative speed Δv (t) with respect to the object at the current time.

  In step 102, the CPU 12A estimates the collision time t_end and the relative speed Δv (t_end) at the time of collision based on the relative distance Δx (t) and the relative speed Δv (t) acquired in step 100, and proceeds to step 104. To do.

  In step 104, the CPU 12A determines whether or not the time until the collision is equal to or less than a predetermined threshold value. In this determination, a time Δt = t_end-t (current time) from the current time and the collision time t_end to the collision is obtained, and it is determined whether or not the time Δt until the collision is equal to or less than a predetermined threshold value. If the determination is negative, the process returns to step 100 and the above processing is repeated. If the determination is affirmative, the process proceeds to step 106.

  In step 106, the CPU 12A sets an occupant target deceleration G_target at the time of collision from the estimation result, and proceeds to step 108. For example, as described above, by using a predetermined model for determining the occupant target deceleration G_target at the time of collision from the time Δt = t_end-t until the collision and the relative speed Δv (t_end) at the time of the collision, An occupant target deceleration (seat target deceleration) G_target at the time of collision is set according to the time Δt = t_end-t and the relative speed Δv (t_end) at the time of collision. Note that step 106 sets the seat target deceleration G_target using a model instead of the occupant target deceleration when considering the behavior of the seat belt and the occupant. Note that the processing in step 106 corresponds to an example of a setting unit.

  In step 108, the CPU 12A determines the seat control force and the seat movement control start time t_start from the time Δt = t_end-t from the current time t to the collision and the target deceleration G_target, and proceeds to step 110. That is, the driving force of the seat drive actuator 18 that generates the target deceleration G_target at the time of collision and the seat control start time t_start that becomes the seat target deceleration G_target at the timing of the collision are determined, and the routine proceeds to step 110. As described above, the seat control force is generated by the seat drive actuator 18 that generates the occupant target deceleration G_target when the rearward movable amount (maximum displacement) of the seat 20 is moved during the time Δt until the collision. Find the driving force. Further, as the drive start timing, the start time t_start of the seat movement control that occurs when the target deceleration G_target is collided is obtained. As the seat control force, for example, a maximum displacement of the seat 20 (amount of backward movement), a time Δt until the collision, and a driving force corresponding to the target deceleration G_target are stored as a predetermined map or the like. It may be determined using a map. Further, the start time t_start may be determined using a map by storing the time Δt until the collision and the start time t_start corresponding to the target deceleration G_target as a predetermined map or the like. Further, the processing in step 108 corresponds to an example of a determination unit.

  In step 110, it is determined whether the CPU 12A and step 114, which will be described later, have already been executed and sheet control is being performed. If the determination is negative, the process proceeds to step 112, and if the determination is negative, the process proceeds to step 118.

  In step 112, the CPU 12A determines whether or not the sheet movement start time t_start determined in step 108 has been reached. If the determination is affirmative, the process proceeds to step 114. If the determination is negative, the process returns to step 100 and the above-described processing is repeated to update the sheet control start time.

  In step 114, the CPU 12A drives the sheet driving actuator 18 to start sheet movement control, and proceeds to step 116.

  In step 116, the CPU 12A determines whether or not the collision detection sensor 16 has detected a collision. If the determination is affirmative, the series of processing ends. If the determination is negative, the processing returns to step 100 and the above processing is repeated, and the seat control force and the seat control start time t_start are sequentially updated.

  On the other hand, in step 110, sheet control has already started, and when the process proceeds to step 118, the CPU 12A determines whether or not it is a time before the sheet movement start time t_start set in step. If the determination is affirmative, the process proceeds to step 120. If the determination is negative, the process proceeds to step 116.

  In step 120, the CPU 12 </ b> A stops the sheet drive actuator 18 to stop the sheet movement control, and then proceeds to step 112. That is, the sheet movement start time t_start is sequentially updated, and if the sheet movement start time t_start is changed to a later time by the update after the sheet movement control is started, the sheet movement control has already started, so the stop Then, after waiting for the updated start time t_start, the sheet movement control is started again. On the other hand, if the sheet movement start time t_start is not changed or is changed at an earlier time, the sheet movement control is continued as it is.

  Here, the results of performing a high-speed full-lap collision test simulation in each of the conventional method (method of driving the seat after the collision occurs to reduce the impact) and the present embodiment will be described.

  FIG. 7A is a diagram showing a waveform example of the occupant deceleration obtained by the high speed full lap collision test simulation in the conventional method. FIG. 7B is a diagram illustrating a waveform example of the occupant deceleration obtained by the high-speed full lap collision test simulation in the present embodiment. FIG. 7C is a diagram showing a waveform example of the displacement of the occupant and the seat with respect to the collision target obtained by the high-speed full-lap collision test simulation according to the conventional method. FIG. 7D is a diagram illustrating a waveform example of the displacement of the occupant and the seat 20 with respect to the collision target obtained by the high-speed full-lap collision test simulation in the present embodiment.

  As shown in FIG. 7A, in the conventional technique in which the seat is driven to mitigate the impact after the collision occurs, the occupant deceleration may suddenly increase from the collision and exceed the impact mitigation reference value. On the other hand, in the present embodiment, as shown in FIG. 7B, since the seat movement is started before the collision and the target deceleration is reached at the time of the collision, the occupant deceleration is dispersed before the collision occurs and the collision occurs. The impact on the occupant can be mitigated without exceeding the upper limit that allows occupant protection later.

  As described above, in the present embodiment, when the collision occurs, the seat movement is started in advance so that the target deceleration of the seat is generated, thereby reducing the deceleration applied to the occupant at the time of the collision and reducing the impact. Can be relaxed.

  Further, with respect to the displacement of the occupant and the seat with respect to the collision target, in the conventional technology in which the seat is driven and the impact is reduced after the occurrence of the collision, as shown in FIG. On the other hand, in this embodiment, as shown in FIG. 7D, it is possible to secure a space for mitigating the impact when a collision occurs without exceeding the upper limit that can protect the occupant.

  Therefore, in the occupant impact mitigating device 10 according to the present embodiment, it is possible to effectively mitigate the impact on the occupant while ensuring a space for mitigating the impact when a collision occurs.

  In the above-described embodiment, the sheet control force when driving the sheet drive actuator 18 is assumed to be constant for the sake of simplicity. However, the sheet control force is not limited to a constant, and a predetermined pattern is used. The seat control force may be used, or the seat control force may be increased or decreased with time.

  Moreover, although the process of FIG. 6 performed by passenger | crew impact mitigation ECU12 in said each embodiment demonstrated as a software process performed when a computer runs a program, it is good also as a process performed by hardware. Alternatively, the processing may be a combination of both software and hardware. Further, a program for processing performed by software may be stored in various storage media and distributed.

  Furthermore, the present invention is not limited to the above, and it goes without saying that various modifications can be made without departing from the spirit of the present invention.

10 Crew Impact Mitigation Device 12 Crew Impact Mitigation ECU
14 Radar Sensor 16 Collision Detection Sensor 18 Seat Drive Actuator 20 Seat 22 Map

Claims (4)

A drive unit for driving a vehicle seat to the rear of the vehicle;
A detection unit that detects the relative distance to the collision target, the relative speed to the collision target, and the relative acceleration to the collision target, or the relative distance and the relative speed, respectively.
Based on the detection result of the detection unit, an estimation unit for estimating the time to the collision and the relative speed at the time of the collision,
When the time until the collision is within a predetermined time, the target deceleration determined based on the estimation result of the estimation unit starts driving the seat to the rear of the vehicle at the driving start timing generated in the seat at the time of the collision. A control unit for controlling the drive unit to
An occupant impact mitigation device.   The control unit uses a predetermined model to set the target deceleration from the estimation result of the estimation unit, and the driving force of the drive unit to generate the target deceleration set by the setting unit And a deciding unit that decides each driving start timing of a seat that occurs when the target deceleration occurs at the time of a collision, and controls the driving unit based on a decision result of the deciding unit. Shock relief device. A detection unit for detecting a collision;
The occupant impact mitigation apparatus according to claim 2, wherein the control unit sequentially updates the driving force and the driving start timing until a collision is detected by the detection unit. The passenger | crew impact mitigation program for functioning a computer as a detection part and control part of the passenger | crew impact mitigation apparatus of any one of Claims 1-3.