Abstract:
A method for alleviating the consequences of a collision of a vehicle, having a front axle and/or a rear axle with at least one roll stabilization device with which torques can be applied in the region of the front axle and/or the rear axle for the purpose of roll stabilization. In order to alleviate the consequences of collisions of vehicles, in the event of a collision protective torques are generated using the roll stabilization devices.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority to German Patent Application No. DE 10 2015 111 154.3, filed Jul. 30, 2015, which is incorporated by reference herein in its entirety. 
       FIELD OF THE INVENTION 
       [0002]    The invention relates to a method and a system for alleviating the consequences of a collision of a vehicle which comprises a front axle and/or a rear axle with at least one roll stabilization device with which opposing torques can be applied for the purpose of roll stabilization in the region of the front axle and/or the rear axle and as a result the consequences of crashes are reduced. 
       BACKGROUND OF THE INVENTION 
       [0003]    German laid-open patent application DE 10 2013 021 485 A1, which is incorporated by reference herein, discloses a method for alleviating the consequences of a collision of a vehicle with a further vehicle, wherein a vehicle level of the vehicle is set as a function of a determined vehicle level of the further vehicle, wherein in addition a horizontal degree of overlap between a deformation area of the vehicle and the further vehicle is determined and an automatic steering intervention for increasing the horizontal degree of overlap is carried out as a function of the determined horizontal degree of overlap. German patent DE 103 32 935 B4, which is incorporated by reference herein, discloses a motor vehicle having a pre-safe system which comprises at least one vehicle-surrounding detection device and a suspension and damping device which is arranged between a vehicle chassis and bodywork and can be actuated as a function of the signals which are received by the vehicle-surroundings-detection device and evaluated in a data-evaluation device, wherein the data-evaluation device of the vehicle-surroundings-detection device is linked to a control unit of an active chassis controller which actuates the suspension and damping device and by means of which a torque which counteracts a tipping moment of the motor vehicle in the direction of the collision object is applied in a pre-crash phase when an impact of a collision object on a side sill area is to be expected, wherein an adjustment time for the adjustment of the vehicle ride level is variable as a function of relative speed with respect to the collision object. 
       SUMMARY OF THE INVENTION 
       [0004]    Described herein is a method and device to alleviate the consequences of collisions of vehicles which comprise a front axle and a rear axle with roll stabilization devices with which opposing torques can be applied for the purpose of roll stabilization in the region of the front axle and the rear axle. 
         [0005]    The method for alleviating the consequences of a collision of a vehicle which comprises a front axle and a rear axle with roll stabilization devices with which opposing torques can be applied in the region of the front axle and the rear axle for the purpose of roll stabilization, is achieved in that in the event of a collision protective torques, which alleviate the consequences of collision, are generated using the roll stabilization devices. Within the scope of the method, for example conventional roll stabilization devices are used in order to generate the protective torques which differ from conventional opposing torques which counteract the rolling torque. 
         [0006]    One preferred exemplary embodiment of the method is characterized in that in the event of an asymmetrical collision alternating torques are generated in the region of the front axle and the rear axle using the roll stabilization devices, which alternating torques have directions of action which are opposed with respect to a rolling axle and which counteract torsion of the vehicle owing to a collision. As a result, in the event of an asymmetrical collision, undesired deformation of the vehicle bodywork can be advantageously reduced. 
         [0007]    A further preferred exemplary embodiment of the method is characterized in that in the event of head-on collision a protective torque is applied in the region of the front axle using the roll stabilization devices, which protective torque is opposed to a protective torque which is applied in the region of the rear axle. In the event of the head-on collision, in particular in the event of an asymmetrical head-on collision, the bodywork of the vehicle can be twisted about its longitudinal axis and/or about its rolling axle. The protective torques which were applied using the roll stabilization devices counteract this twisting. 
         [0008]    A further preferred exemplary embodiment of the method is characterized in that the protective torques have the same directions of action in the region of the front axle and of the rear axle. As a result, for example better overlap with respect to a crash barrier can advantageously be provided. 
         [0009]    A further preferred exemplary embodiment of the method is characterized in that the protective torques in the region of the front axle and the rear axle are applied in such a way that an overlap between the vehicle and an obstacle is increased when the collision occurs. The ride level of the vehicle can be raised or lowered on one side as a function of the obstacle. 
         [0010]    A further preferred exemplary embodiment of the method is characterized in that the protective torques are applied in the region of the front axle and the rear axle in such a way that an alternative crash structure is loaded when the collision occurs. This permits impact energy during the collision to be advantageously dissipated. 
         [0011]    In the case of a system for alleviating the consequences of a collision of a vehicle which comprises a front axle and a rear axle with roll stabilization devices, with which opposing torques which counteract a rolling torque can be applied in the region of the front axle and the rear axle for the purpose of roll stabilization, the abovementioned object is alternatively or additionally achieved in that in the event of a collision the protective torques which alleviate the consequences of the collision are generated using the roll stabilization devices, in particular according to a method described above. 
         [0012]    The invention also relates to a computer program product having a program code for carrying out a method described above. The computer program is executed, for example, in a control unit of the motor vehicle. 
         [0013]    The invention also relates to a control unit for controlling roll stabilization having such a computer program product. The control unit advantageously interacts with a vehicle-surroundings-detection device and the roll stabilization devices of the vehicle. 
         [0014]    The invention also relates to a motor vehicle having roll stabilization and having a control unit as described above. The roll stabilization comprises, for example, roll stabilization devices such as are disclosed in the German laid-open patent application DE 10 2010 010 869 A1, which is incorporated by reference. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    Further features, advantages and details of the invention can be found in the following description in which various exemplary embodiments are described in detail with reference to the drawing, in which: 
           [0016]      FIG. 1  shows a perspective illustration of a conventional vehicle having roll stabilization. 
           [0017]      FIG. 2  shows the vehicle from  FIG. 1 , wherein arrows indicate how in the case of a collision protective torques which alleviate the consequences of the collision are generated using the roll stabilization. 
           [0018]      FIG. 3A  depicts a schematic diagram of the roll stabilization device of the vehicle. 
           [0019]      FIG. 3B  depicts a schematic view of the roll stabilization device of the vehicle as viewed from one side. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0020]      FIG. 1  is a simplified perspective illustration of a vehicle  1  having a vehicle bodywork  3 . The vehicle  1  comprises a front axle  5  and a rear axle  6 . A rolling axle  7  runs between the front axle  5  and the rear axle  6 . A rolling torque, which occurs during operation of the vehicle  1  and acts around the rolling axle  7  is indicated by an arrow  9 . The front axle  5  comprises suspension means (not denoted in more detail) for two front wheels  11  and  12 . The rear axle  6  analogously comprises suspension means (not denoted either) for rear wheels  13 ,  14 . 
         [0021]    Furthermore, the front axle  5  comprises a roll stabilization device  15 . The rear axle  6  comprises a roll stabilization device  16 . Opposing torques which are generated by the roll stabilization devices  15 ,  16  are indicated by arrows  17 ,  18 . The opposing torques  17 ,  18  counteract the rolling torque  9 . 
         [0022]      FIG. 2  illustrates a similar vehicle  21  to that in  FIG. 1 . The same reference symbols are used to denote the same or similar parts. In order to avoid repetition, reference is made to the preceding description of  FIG. 1 . 
         [0023]    In  FIG. 2 , torques which act on the vehicle  21  in the region of the front axle  5  and the rear axle  6  in the event of collision of the vehicle  21  are indicated by arrows  24 ,  25 . The torque  24  acts in the region of the front axle  5 . The torque  25  acts in the region of the rear axle  6  and is opposed to the torque  24 . 
         [0024]    The torques  24 ,  25  which act in opposing directions bring about torsion of the bodywork  3  of the vehicle  21  owing to a crash. The torques  24 ,  25  are triggered, for example, by asymmetrical crash events. The torsion of the vehicle  21  which is caused by the crash is undesired because it can bring about intrusions and deformations at the vehicle  21 . 
         [0025]    Protective torques which as a result of alternating responses of the roll stabilization bring about torsion of the vehicle bodywork  3  in opposition to the torsion  24 ,  25  owing to the crash are indicated by arrows  27 ,  28 . As a result, undesired deformation of the vehicle bodywork  3  can be prevented or reduced. 
         [0026]    A controller unit which is connected in terms of control (not illustrated) to the roll stabilization devices  15 ,  16  of the vehicle  21  is indicated by means of a rectangle  30 . The protective torque  27  is applied in the region of the front axle  5  of the vehicle  21  using the roll stabilization device  15 . 
         [0027]    The protective torque  27  is opposed to the torque  24  owing to the crash. The protective torque  28  is applied in the region of the rear axle  6  of the vehicle  21  by means of the roll stabilization device  16 . The protective torque  28  is opposed to the torque  25  owing to the crash. 
         [0028]    The roll stabilization with the roll stabilization devices  15 ,  16  is also referred to as an anti-roll system. The anti-roll system serves to prevent undesired rolling movement of vehicle  1 ;  21  at the front axle  5  or the rear axle  6  about the rolling axis  7  of the vehicle  1 ;  21 . 
         [0029]    The roll stabilization devices  15 ,  16  comprise, for example, actuators which are embodied as hydraulic cylinders. Hydraulic pressure can be selectively applied to working spaces of the actuators in an alternating fashion via actuator lines, in order, for example, to minimize the rolling angle when the vehicle  1 ;  21  is cornering. 
         [0030]    In the case of the vehicle  21 , the roll stabilization devices  15 ,  16  are used to generate the protective torques  27 ,  28  in the event of a collision. The protective torques  27 ,  28  which are illustrated in  FIG. 2  act in opposing directions. Therefore, the term alternating response of the roll stabilization is used. 
         [0031]    The alternating response of the roll stabilization or of the anti-roll system serves to apply the opposing torque which is described above in order to counteract the undesired deformation of the vehicle bodywork  3 . 
         [0032]    In contrast to the illustrations, in the event of a collision rolling of the vehicle bodywork  3  of the vehicle  21  can also be applied on the same side using the roll stabilization devices  15 ,  16 . 
         [0033]    In the case of simultaneous rolling on the same side, protective torques are generated in the same direction with the roll stabilization devices  15 ,  16  and applied in the region of the front axle  5  and the rear axle  6  of the vehicle  21 . Rolling of the vehicle  3  on the same side is helpful, for example, in providing a better overlap between vehicle bodywork  3  of the vehicle  21  and a crash barrier (not illustrated). 
         [0034]      FIG. 3A  depicts a schematic diagram of the roll stabilization device  15  of the vehicle  21 , and  FIG. 3B  depicts a schematic view a portion of the roll stabilization device  15  as viewed from one side. Although not described, it should be understood that roll stabilization device  16  shares the same structure and functionality as roll stabilization device  15 . 
         [0035]    Roll stabilization device  15  includes a drive unit  40 , which may be an electric motor or a hydraulic actuator, for example. A gear box  42  is mounted to the output shaft of the drive unit  40 . Gear box  42  is mechanically connected to an anti-roll bar  44  by gearing, for example. Anti-roll bar  44  is either connected to or associated with front axle  5  of vehicle  21 . Anti-roll bar  44  is connected to the top end of the central rod of strut  46 . 
         [0036]    In operation, drive unit  40  rotates gear box  42 , which rotates anti-roll bar  44  about axis  48 , which causes strut  46  to either expand or contract (depending upon the rotational direction of drive unit  40 ) for counteracting the torque  24  owing to the crash. According to the example shown in  FIGS. 3A and 3B , the torque  24  owing to a vehicle crash causes strut  46  to elongate in the direction of arrow  50 . Concurrently, roll stabilization device  15  actuates drive unit  40  to rotate anti-roll bar  44  and cause strut  46  to retract in the opposite direction of arrow  50 , which is shown by arrow  52 , thereby equalizing the elongation of the strut  46  caused by the crash.