DE102017222389B4 - A method for operating a motor vehicle upon detection of an unavoidable side impact on a vehicle-foreign object - Google Patents

Abstract

Method for operating a motor vehicle (K1) upon detection of an unavoidable side impact on a vehicle-foreign object, characterized in that at least one wheel (HL, VL or HR, VR) facing the vehicle-external object is moved by the motor vehicle (K1) in a movement (S, T) is moved automatically such that a distance of the wheel (HL, VL or HR, VR) is reduced to the vehicle-foreign object, wherein after movement (S, T) of the wheel (HL, VL or HR, VR) at least one airbag (6) is brought by ignition in such a position in which it additionally supports the wheel (HL, VL or HR, VR) against a side impact force (Fa).

Description

The invention relates to a method for operating a motor vehicle upon detection of an unavoidable side impact on a vehicle-foreign object.

Such a method is known from DE 10 2009 037 749 A1 known. Specifically, it is proposed in this document to monitor the environment of the motor vehicle by a vehicle environment recognizer. Upon detection of an imminent side impact with another motor vehicle, automatic steering movement toward the impending side impact side is caused such that the vehicle body is raised on the side of the impact by the steering movement and resulting roll of the vehicle body.

From the DE 103 52 212 A1 is also a generic method known. In this method, it is proposed to effect a position determination of the vehicle body at least on the collision side as a function of a determined collision area. In this way, the vehicle body to be raised and / or lowered in an optimal collision position, so that arranged on the motor vehicle, passive safety devices such. As the side skirts, can unfold their optimal effect in a side collision. In addition to raising and / or lowering the vehicle body, deceleration of the vehicle is suggested. As a result, for example, in the event of an impending side collision, the possible impact area due to the deceleration of the vehicle is to be displaced from the vehicle door into the fender area, in order to be able to advantageously reduce the occupant load.

In which also the features of the preamble of claim 1 having DE 10 2011 101 009 A1 a collision protection device for a motor vehicle is described. The collision protection device has an impact element that can be extended before or during a collision of the vehicle. The extendable impact element is arranged in the region of a longitudinal member of the motor vehicle and controlled by a control unit. The control unit is connected to a detection unit, by means of which a motor vehicle imminent or a successful side collision can be detected.

From the WO 2014/015094 A2 a protective element connected to the vehicle structure has become known, which ramps out laterally in the event of a detected offset collision with the assistance of a fired airbag. As a result, in the case of the collision, the movement trajectory of the motor vehicle should be moved away from the collision obstacle. Alternatively, it is proposed to displace a front-side pivot point of the collision-facing front wheel outward via a piston-cylinder unit so as to turn the wheel so that the tire of the wheel can act as a shock-absorbing member between the impact obstacle and the vehicle.

Finally, in the US Pat. No. 9,623,712 B2 proposed a vehicle front structure, with which the wheels are connected such that they partially detach from the vehicle structure in an eventual collision and can perform an outward and rearward evasive movement.

Based on this prior art, the present invention, the object of the invention to provide a method having the features of the preamble of claim 1, which provides an improved security in the event of a side impact to an occupant. Furthermore, the invention is based on the object to provide a motor vehicle, with which the method is easy to carry out.

From the DE 10 2011 056 240 B3 a motor vehicle is known, comprising four wheels, which are arranged by means of suspension elements on a supporting structure of the motor vehicle. Furthermore, the motor vehicle comprises a sensor device, by means of which it can be determined whether a collision of the motor vehicle with a colliding object is imminent or occurs, wherein the motor vehicle comprises at least one weakening device activatable by the sensor device for targeted structural weakening of at least one wheel suspension element of at least one wheel. Furthermore, it can be determined by means of the sensor device whether and on which vehicle side a side impact of a colliding object is imminent or occurs on the motor vehicle, whereby at least one weakening device can be activated on a vehicle side facing away from the colliding object by means of the sensor device, so that a frictional resistance is caused by buckling of at least one wheel can be reduced between the motor vehicle and a road. It can further be provided that at least one weakening device can additionally be activated on a vehicle side facing the colliding object by means of the sensor device.

From the DE 10 2015 012 538 A1 a suspension is known in which the wheel on a wishbone with two angularly disposed legs, of which in an initial state of the suspension a longitudinal leg Towards the direction of travel is directed backwards and has a rear end, and a transverse leg is directed perpendicular to the direction of travel to the outside, and having an outer end is suspended. In this case, a wheel bearing device in the region in which meet the two legs, a front bearing means and provided at the rear end of the longitudinal leg, a rear bearing means at the outer end of the transverse leg. In this case, an adjusting device is provided which engages the rear bearing device at the rear end of the longitudinal limb of the wishbone and, in the event of a crash, causes the rear end of the longitudinal limb to be displaced outwards. In this case, the front and rear bearing device are dimensioned so that in the event of a crash, the front bearing device fails earlier than the rear bearing device.

With regard to the method, the object is achieved by a method having the features of patent claim 1. A motor vehicle with the features of claim 5 solves the further object.

Advantageous developments or training can be found in the respective dependent claims.

With regard to the method, a method is assumed for operating a motor vehicle when an unavoidable side impact on a vehicle-foreign object is detected. The vehicle-foreign object may be, for example, another moving motor vehicle. However, it is also conceivable that the vehicle-foreign object is formed by a stationary or stationary obstacle.

The invention now proposes that at least one wheel facing the vehicle-external object, that is to say the expected side impact, be moved by the motor vehicle in a movement in such a way that a distance of the wheel from the vehicle-foreign object is reduced.

In this way, by means of a component which is already present in the motor vehicle, laterally an additional deformation structure in the manner of a crumple zone can be realized. Thus, early contact of the wheels with the vehicle-foreign object is made possible before contact of the vehicle-external object with the actual vehicle cabin occurs. This leads to a timely energy reduction and thus the impact energy acting on the occupants.

Further, after the movement of the wheel at least one airbag is brought by ignition in such a position in which it additionally supports the wheel against a side impact force.

For example, it is conceivable that the airbag is located in the wheel housing of the motor vehicle and fills the space created by the extension of the wheels clearance between the wheel and the wheel arch or the body after ignition. Side impact forces acting on the wheels can thus be conducted and distributed even better on the body structures located behind the airbag, such as side members and / or wheel housing.

According to one embodiment, it is proposed that the wheel is moved in a translatory movement in the direction of the vehicle-foreign object. These features make a structurally very simple realization of the method possible. Since the translational movement also represents a direct route to the vehicle-foreign object, the movement can take place in a very short time.

According to another embodiment of the inventive concept, when a high probability of a side impact, in which the side impact is not yet considered unavoidable, is detected, a movement mechanism responsible for the said movement is preconditioned. In other words, the responsible movement mechanism is already forewarned, so that its reaction time in case of a necessary movement of the wheel at the "starting shot" as short as possible fails.

In one embodiment, the expected severity of the side impact is estimated and, depending on this, an extension path of the wheel is dimensioned and / or pressure valves of the airbag are activated. In this way, an optimal and at the same time adaptive energy absorption can be achieved by a support structure of the wheel and / or the airbag. As already mentioned, it is thus possible by means of the extendable wheel to generate an additional crumple zone for the motor vehicle in the lateral area. Furthermore, an early coupling of the motor vehicle with the vehicle-foreign object is achieved. As a result, the acceleration can be reduced to the occupants, as more way and thus more time is available to reduce the impact energy.

Particularly in the case of short vehicle types, for example small cars, overlapping with at least one of the two wheels with the frontal architecture of a laterally impinging motor vehicle is highly probable in the event of a side impact. The wheels, which can take up to one-third of the side of the vehicle body, thus have a significant impact on a side impact. Ideally, the frontal architecture of a side impact vehicle covers both wheels of one's own motor vehicle, so that the Wheel structures of both wheels can absorb energy and consume.

It is therefore expedient if, when an unavoidable side impact is detected on a vehicle-foreign object, both wheels facing the vehicle-external object are extended by the motor vehicle.

With the invention, a motor vehicle to be placed under protection, which is well suited for carrying out the method according to the invention.

Such a motor vehicle is characterized by wheels, which are each coupled in terms of movement with a movement device or drive unit such that the wheels as a whole can be moved outward out of the motor vehicle. In this way, an additional deformation structure can be created very effectively by the wheels in the side area.

In this case, each wheel is associated with at least one airbag, which can be brought into a position located between the vehicle body and the wheel after ignition. The vehicle body can be formed for example by a longitudinal member located behind the wheel or a wheel house. In any case, this is a very effective, additional support against lateral impact forces possible.

In order to keep the design effort as low as possible, it is proposed that the drive unit has a lifting piston, which is connected to a wheel carrier and pneumatically or hydraulically extendable outwardly from a lifting cylinder. The movement of the wheels thus takes place, so to speak, in the manner of a parallel displacement to the outside. This is very fast and efficient feasible.

In addition, it is conceivable that the wheels each have a separate deformation structure, which is aligned with an impact force acting laterally on the wheels. The separate deformation structure is based on an ordinary rim geometry or rim structure. In this way, therefore, even additional energy reduction can be achieved by the deformation of the wheels.

In a further embodiment of the invention, it is conceivable that the deformation structure in the direction of the impact force is cone-shaped or conical. Such a deformation structure is structurally easy and inexpensive to implement.

A preferred embodiment of the invention is illustrated in the figures and will be explained in more detail with reference to the figures in the following description. As a result, even further advantages of the invention become apparent. The same reference numerals, even in different figures, refer to the same, comparable or functionally identical components. In this case, corresponding or comparable properties and advantages are achieved, even if a repeated description or reference does not occur. The figures are not always to scale. In some figures, proportions may be exaggerated to more clearly highlight features of an embodiment.

• 1 zwei Kraftfahrzeuge auf Kollisionskurs, mit einem ersten Abstand,
• 2 die zwei Kraftfahrzeuge kurz vor einem unvermeidbaren Aufprall,
• 3 die zwei Kraftfahrzeuge noch etwas kürzer vor dem unvermeidbaren Aufprall,
• 4 die zwei Kraftfahrzeuge bei erfolgendem Aufprall,
• 5a eine Detaildarstellung gemäß Detail V aus 1, im Normalbetrieb des Kraftfahrzeugs,
• 5b eine Darstellung gemäß 5a, mit seitlich ausgefahrenem Vorderrad,
• 5c eine Darstellung gemäß 5b, mit zusätzlich gezündetem Airbag,
• 6 die Darstellung einer möglichen Radgeometrie, welche als Deformationsstruktur wirken kann und
• 7 die Darstellung eines zur Durchführung des Verfahrens geeigneten Kraftfahrzeugs, in einer zweiten Ausführungsform.

It show, each schematically

• 1 two motor vehicles on a collision course, with a first distance,
• 2 the two motor vehicles on the verge of an unavoidable impact,
• 3 the two cars a little shorter before the inevitable impact,
• 4 the two motor vehicles upon impact,
• 5a a detailed representation according to detail V from 1 , in normal operation of the motor vehicle,
• 5b a representation according to 5a , with laterally extended front wheel,
• 5c a representation according to 5b , with additionally ignited airbag,
• 6 the representation of a possible wheel geometry, which can act as a deformation structure and
• 7 the representation of a vehicle suitable for carrying out the method, in a second embodiment.

In 1 are a first motor vehicle K1 and a second motor vehicle K2 shown. In the motor vehicle K1 it may, for example, be an autonomously driving motor vehicle.

The motor vehicles K1 and K2 each have a left front wheel VI , a right front wheel Vr , a left rear wheel HI and a right rear wheel Mr , In the motor vehicles K1 and K2 there are inmates IN , With X is a vehicle longitudinal direction and with Y a vehicle transverse direction numbered.

The car K1 is equipped with environment sensors that allow objects in the near and far surroundings to be detected. The environmental sensor system includes, among others, precrash sensors 12 which on the sides and at the ends of the motor vehicle K1 are installed. The precrash sensors 12 For example, they may be in the form of ultrasonic sensors. However, the environment sensor system can also replace or in addition Cameras, lidar and / or radar sensors include (not shown).

Further, a control unit 11 present, which signaling with the environment sensors or with the precrash sensors 12 connected is.

The motor vehicle K1 drives at a speed v1 , the motor vehicle K2 at a speed v2 , It can be seen that the motor vehicle K2 on a collision course with the motor vehicle K1 located. The car K2 only has a small distance a1 to the motor vehicle K1 on. The distance a1 is already so low that due to the precrash sensors 12 to the evaluation and control unit 11 forwarded signals cause a collision protection device or a movement mechanism is preconditioned for it. The collision protection device consists of the laterally extendable wheels VI . HI respectively Vr and Mr , which additionally each an airbag is assigned (will be described in more detail later). Depending on the environment sensor of the motor vehicle K1 determined relative speed between the motor vehicles K1 and K2 , the estimated mass of the motor vehicle K2 as well as its expected impact area become required process parameters for controlling the collision device of the motor vehicle K1 preset.

This concerns, for example, the degree of filling of the airbags, as well as the size of the lateral extension of the laterally extendable wheels VI . HI and Vr . Mr from the motor vehicle K1 , By means of said preconditioning, valuable time can be saved in the event of a crash or when the collision protection device is triggered. Everything happens in the millisecond range.

In the 2 is shown a little later time, to which already a much smaller distance a2 between the vehicles K1 and K2 consists. The distance a2 is now so low that those of the precrash sensors 12 forwarded signals from the evaluation and control unit 11 be interpreted such that an unavoidable impact of the motor vehicle K2 on the motor vehicle K1 imminent.

Therefore are from the evaluation and control unit 11 Drive units of the motor vehicle K2 facing wheels VI and HI so driven that the wheels VI and HI in the direction of the motor vehicle K2 to be moved. So it will be the distance of the wheels VI and HI to the motor vehicle K2 reduced.

The movement of the wheels VI and HI is preferably in a translatory movement T completed. This is the extension of the wheels VI . HI very fast and effectively possible.

In 3 is shown a little later date at which there is already a distance a3 between the motor vehicles K1 and K2 has resulted. The distance a3 is still a little less than the distance a2 ,

It can be seen that in addition to the lateral extension of the wheels VI and HI ignited airbags 6 ' are shown, which respectively the wheels VI and HI assigned.

In particular, the ignited airbags 6 ' in the wheel arches between the vehicle body and the extended wheels VI . HI positioned, as will be shown in more detail later.

4 shows the state of the taking place side impact of the motor vehicle K2 on the motor vehicle K1 , By an effective impact force fa become the wheels VI and HI deformed (see petted implied contours of the deformed wheels VI ' and hl ' ). As a result, a large part of the impact energy can already be reduced. In addition, the ignited airbags allow 6 ' a large-area support of the wheels VI and HI against the vehicle body, a further reduction of the impact energy as well as a good transmission of the impact energy into the vehicle structure.

All this leads to being on the inmates IN acting, impact-induced accelerations can be reduced.

Based on 5 is one through each wheel of the motor vehicle K1 formed collision protection device exemplified for the left front wheel VI shown.

In the 5a is the front end structure of the motor vehicle K1 partly visible. The wheel VI is in the longitudinal direction of the motor vehicle K1 seen between a front bumper cross member 5 and an inner cross member 13 arranged. The bumper cross member 5 and the cross member 13 are over a side member 2 with upstream crash box 4 connected with each other. With 10 is a sill of the motor vehicle K1 quantified.

The wheel VI as well as the other wheels Vr . HI and Mr are driven by a wheel hub motor, not shown. Other drive concepts are quite conceivable.

Further, a drive unit 9 visible, which for lateral extension of the wheel VI serves. The drive unit 9 is preferably as a unit of a reciprocating piston 9a and one lifting cylinder 9b educated. This is the reciprocating piston 9a with a wheel carrier 1 firmly connected. The reciprocating piston 9a is longitudinally displaceable in the lifting cylinder 9b guided.

As an alternative embodiment of the drive unit 9 is also a rack drive, a spindle drive or the like conceivable. However, the illustrated drive unit offers 9 the advantage of a very fast extendability.

As will be further apparent from the figure, is a lifting chamber 9c in which the reciprocating piston 9a slidably guided, technically with a pressure generator 8th connected. The pressure generator 8th For example, it can work hydraulically or pneumatically.

The pressure generator 8th is in turn via a signal line 14 with the already mentioned evaluation and control unit 11 connected by signal technology. The evaluation and control unit 11 is in turn via a signal line 14 Signaling with one or more precrash sensors 12 connected. The signaling connection between said components can also be realized by means of a bus system, for example by means of a CAN or LIN bus system.

Furthermore, in the figure of the wheel VI assigned airbag 6 recognizable, which still folded on the side member 2 is arranged. The airbag 6 is a gas generator 7 associated with the airbag 6 is inflatable or ignitable. The gas generator 7 is also via a signal line 14 signaling with the evaluation and control device 11 connected and controlled by this.

5b shows the state in which of the evaluation and control unit 11 based on the data of the precrash sensor 12 an unavoidability of a side impact was detected.

Already in advance were from the evaluation and control unit 11 the possible impact location, the possible impact speed and also the probable accident severity of the collision determined and carried out at a high collision probability preconditioning of each collision protection device. A collision protection device is in the embodiment, for example, by the extendable wheel VI , its drive unit 9 as well as the airbag 6 together with gas generator 7 educated.

From the state of the preconditioning is done by the evaluation and control unit 11 the pressure generator 8th driven. This causes the lifting chamber 9c is filled with fluid (oil or air) and thereby the reciprocating piston 9a together with the bike VI in a translatory movement T around an extension path a outward from the lift cylinder 9b is proceeding (see VI ' ).

In addition, a disc-like cover 3 be present, which is the wheel VI covers.

By the extended wheel VI ' An additional lateral crumple zone is created that can help reduce impact energy.

In the 5c Another stage of the process is shown in which after the extension of the wheel VI the gas generator 7 through the evaluation and control device 11 was controlled so that thereby the airbag 6 inflated or ignited (compare 6 ' ). When inflated, the airbag is located 6 ' between the extended wheel VI ' and the vehicle body, for example, the side member 2 , This allows an additional support of the wheel VI ' , in addition to support against the drive unit 9 , be achieved.

About also through the evaluation and control unit 11 controllable valves 6a of the airbag 6 ' also allows the outflow behavior of the airbag 6 ' to be influenced. As a result, depending on the expected hardness of the impact, the "softness" of the airbag 6 ' to be influenced.

In order to additionally reduce impact energy effectively, it may be advantageous if the wheel VI itself, specifically its rim geometry, has an additional deformation structure.

A possible deformation structure 15 is in 6 shown. The deformation structure 15 consists of an outside wheel part 15a and an inside wheel part 15b , The wheel parts 15a and 15b are pushed together and at attachment points 15c firmly connected. The attachment points 15c can be realized for example by spot welding.

In addition to the usual rim geometry, which is an outside rim flange 16a and an inside rim flange with intermediate rim bed 17 has, is the deformation structure 15 characterized in that the rim base 17 through an outside rim bed 17a and an inside rim base 17b is formed, which is in an overlap area 18 overlap.

In particular, the outside rim base is 17a conical, so in the direction of the inside rim base 17b formed rejuvenating. The inside rim base 17b on the other hand, it is funnel-like, becoming the outside rim base 17a widening trained.

Occurs now in a side impact, an impact force fa On, which exceeds a certain limit, this leads to the fact that the outside rim base 17a in the inside rim 17b into it and thereby a deformation (widening) of the inside rim base 17b takes place. As a result, additional impact energy can be reduced.

Finally, based on the 7 yet another motor vehicle K3 be described, which is also suitable for carrying out the method according to the invention.

In the motor vehicle K3 the movement of the wheels takes place upon detection of an unavoidable side impact not by a translational movement, but by a pivoting movement S , The necessary drive units are not shown in detail. They are also structurally complex than those of the motor vehicle K1 ,

However, this offers the possibility of the position of the wheels Vr . Mr respectively VI . HI depending on the expected impact area in their X Position to change.

For example, an existing distance in normal operation a4 between the wheels Vr and Mr by a pivoting movement directed towards each other S of these wheels at a distance a5 be reduced (cf. Vr ' and Mr' ). Also, while the distance of the wheels VR, Hr to a motor vehicle K2 reduced.

The advantage is that by the pivoting movement S an overlap area to a laterally colliding object, for example to a motor vehicle K2 can be significantly increased in this way.

It is also conceivable that each of the wheels Vr and Mr in an opposite pivoting movement S is moved (see. Vr " and Mr" ). This can be useful, for example, if the expected impact location of an impact object further in the front or in the rear of the force range K3 takes place.

LIST OF REFERENCE NUMBERS

1

wheel carrier

2

longitudinal beams

3

cover

4

crash box

5

Bumper crossmember

6, 6 '

air bag

6a

valves

7

inflator

8th

pressure generator

9

drive unit

9a

reciprocating

9b

lifting cylinder

9c

stroke chamber

10

sill

11

Evaluation and control unit

12

Pre-crash sensor

13

crossbeam

14

signal lines

15

deformation structure

15a

outside wheel part

15b

inside wheel part

15c

attachment points

16a

outside rim flange

16b

inside rim flange

17

rim

17a

outside rim base

17b

inside rim bed

18

overlap area

a

extension path

a1-a5

distances

fa

impact force

IN

inmate

K1-K3

motor vehicles

VI, VI '

left front wheel

Vr, Vr ',

right front wheel

Hl, Hl '

left rear wheel

Mr., Hr '

right rear wheel

S

pivotal movement

T

translational movement

v1, v2

speed

X

Vehicle longitudinal direction

Y

Vehicle transverse direction

Claims (8)

Method for operating a motor vehicle (K1) upon detection of an unavoidable side impact on a vehicle-foreign object, characterized in that at least one wheel facing the vehicle-external object (HL, VL or HR, VR) is automatically moved by the motor vehicle (K1) in one movement (S, T) in such a way that a distance of the wheel (HL, VL or HR, VR) from the vehicle-foreign object is reduced, wherein after movement (S, T) of the vehicle Rades (HL, VL or HR, VR) at least one airbag (6) is brought by ignition in such a position in which it additionally supports the wheel (HL, VL or HR, VR) against a side impact force (Fa). Method according to Claim 1 , characterized in that the wheel (HL, VL or HR, VR) is moved in a translational movement (T) in the direction of the vehicle-foreign object. Method according to Claim 1 or 2 , characterized in that upon detection of a high probability of a side impact, a movement mechanism (S, T) in charge of the movement mechanism is preconditioned. Method according to one of the preceding claims, characterized in that the expected severity of the side impact is estimated and in dependence therefrom an extension path (a) of the wheel (HL, VL or HR, VR) and / or Druckvenrtile (6a) of the airbag ( 6) are controlled. Motor vehicle (K1) for carrying out the method according to one of the preceding claims, characterized by wheels (HL, VL or HR, VR) which are each coupled in terms of movement with a drive unit (9) such that the wheels (HL, VL or HR, VR) as a whole can be moved outward out of the motor vehicle (K1), wherein each wheel (HL, VL or HR, VR) is assigned at least one airbag (6) which after being ignited in one between the vehicle body and the wheel (HL, HL). VL or HR, VR) position can be brought. Motor vehicle (K1) after Claim 5 , characterized in that the drive unit (9) has a lifting piston (9a) which is connected to a wheel carrier (1) and pneumatically or hydraulically outwardly from a lifting cylinder (9b) is extendable. Motor vehicle (K1) according to one of Claims 5 or 6 , characterized in that the wheels (HL, VL, HR, VR) each have a separate deformation structure (15) which is aligned with a side impact on the wheels (HL, VL or HR, VR) impact force (Fa). Motor vehicle (K1) after Claim 7 , characterized in that the deformation structure (15) in the direction of the impact force (Fa) is cone-shaped or conical.

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