The present invention relates to a system for generating a triggering signal for restraining means in a vehicle, the restraining means being provided for the event of a collision of the vehicle, such as a head-on collision or a side impact. To that effect, the system includes means for detecting an impact which, in the event of an impact, generate a request signal for the restraining means corresponding to the type of impact. Means for detecting a rotational motion of the vehicle about at least one vehicle axis are additionally provided.
Furthermore, the present invention relates to a method for triggering restraining means which are provided for the event of a collision of the vehicle. In addition to information about a possible collision of the vehicle, information about a possible rotational motion of the vehicle about at least one vehicle axis is collected and analyzed.
In the conventional vehicles which are equipped with restraining means, triggering of the restraining means in accidents involving a head-on collision or a side impact normally takes place independently from the circumstances of the accident. In particular, it is not taken into account in the conventional triggering algorithms whether a rollover takes place or has already taken place during the course of the accident. Due to this fact, the driver airbag and the front passenger airbag may be deployed, for example, even though the vehicle is lying on its roof after a rollover, the passenger compartment has been made smaller by the rollover, and the passengers are situated in an undefined position. If the vehicle lands on its side during a rollover, triggering of the particular side airbag is at least critical when a vehicle passenger is situated directly above the side airbag. Overall, practice has shown that in accidents in the course of which a critical rotational motion of the vehicle occurs in addition to an impact, a not negligible injury risk for the vehicle passengers emanates from triggering the restraining means provided for the impact situation. Protection of the vehicle passengers may be improved in that the circumstances of the accident are taken into account in the decision about triggering the restraining means
The present invention improves the passenger protection by refining the criterion for triggering the restraining means provided for impact situations. To this end, information about the possible occurrence or existence of a rotational motion of the vehicle is taken into account in the decision about triggering these restraining means. According to the present invention, this is implemented by using a circuit which, for generating a triggering signal, combines the request signal and the status signal—and thus the information about the circumstances of the accident.
The present invention utilizes the fact that it is reasonable to coordinate the use of all restraining means situated in the vehicle, in particular when the vehicle rolls over during the course of an accident, or when the vehicle experiences a critical rotational motion in which the vehicle topples over on the side, for example. In addition, it is recognized according to the present invention that in such accidents triggering of the restraining means, which are supposed to protect the vehicle passengers during a critical rotational motion of the vehicle such as a rollover, has a higher priority than triggering of the restraining means provided for impact situations. Therefore, the criterion for triggering these restraining means is refined according to the present invention. According to the present invention, information is used for refining the triggering criterion which is collected and analyzed for determining a critical rotational motion of the vehicle since the position and the state of the vehicle, as well as the position of the passengers in the passenger compartment, may be estimated relatively easily using this information. On the basis of this estimation, it may then be better decided whether it is sensible or even detrimental to the protection of the passengers to trigger the restraining means provided for the present impact situation.
In an example embodiment of the present invention, it is provided to block the restraining means in the event of an impact situation for a defined period of time tstop when a critical rotational motion of the vehicle has been recognized. The circuit of the system according to the present invention includes at least one hold element for this purpose, with which period of time tstop, in which no triggering signal may be generated, is determined. The circuit and the hold element in particular are designed in such a way that, in the event of a collision, the restraining means are only blocked when additionally a critical rotational motion is also recognized. For this purpose, the information about the possible occurrence or existence of a rotational motion of the vehicle is analyzed based on one or also multiple criteria which may differ from vehicle type to vehicle type and may be predefined by the vehicle manufacturer.
When the vehicle rolls over prior to impact, it is oftentimes reasonable to block or at least to delay triggering of the restraining means. In order to recognize such situations, the vehicle's instantaneous angular position (αx and/or αy) is detected and analyzed in an example embodiment of the present invention. Whenever the instantaneous angular position (αx and/or αy) exceeds a first appropriately selected threshold value (αx min1 and/or αy min1) it is assumed that a rollover is taking place or has taken place, which is recognized as a rotational motion in the context of the present invention.
Furthermore, it may be reasonable to block or at least to delay triggering of the restraining means as soon as a rollover is predicted, i.e., the vehicle has not yet rolled over, but a rollover is imminent. For recognizing such situations it is provided according to the present invention to also detect and analyze the vehicle's instantaneous angular velocity (ωx and/or ωy) in addition to the instantaneous angular position (αx and/or αy). A rollover may be easily predicted in this case and the existence of a critical rotational motion may thus be assumed when the instantaneous angular position (αx and/or αy) exceeds a second appropriately selected threshold value (αx min2 and/or αy min2), and when the instantaneous angular velocity (ωx and/or ωy) also exceeds an appropriately selected threshold value (ωx min and/or ωy min).
It should be noted at this point that the occurrence of a rollover may be recognized or predicted using other motion parameters which may likewise be detected and analyzed with the help of a system according to the present invention and within the scope of the method according to the present invention. In addition, other or more rotational motions of the vehicle may be defined as being critical.
As already mentioned, the criteria on the basis of which a possible rotational motion of the vehicle is classified as being critical or uncritical may be determined by the vehicle manufacturer for example. In addition, period of time tstop in which the restraining means are blocked may be determined individually, namely not only dependent on the vehicle type but also dependent on the circumstances of the accident. In the event of an impact, the restraining means may be blocked permanently (tstop=∞) for example or only for a limited period of time (tstop=const.) when a critical rotational motion has been recognized.
Oftentimes it is advantageous to block the restraining means at least until the vehicle has come to rest. To determine this, a third threshold value for the instantaneous angular position (αx and/or αy) for example may be defined. If the instantaneous angular position (αx and/or αy) falls below this third threshold value (αx min3 and/or αy min3) it may be assumed that the vehicle has come to rest. Detecting and analyzing the vehicle's instantaneous linear acceleration (ax, ay and/or az) presents another possibility. In this case, for example, it may then be assumed that the vehicle has come to rest when a function of the instantaneous linear acceleration f (ax, ay and/or az) falls below a defined threshold value amin.
a through 1c each show a block diagram of an example embodiment of a system according to the present invention for generating a triggering signal for restraining means in a vehicle.
a through 2d each show a block diagram of an example embodiment of the hold element of a system according to the present invention.
Example systems 1, 2 and 3 according to the present invention described below in connection with
According to the present invention, each of systems 1, 2, or 3 includes a circuit 11, 21, or 31 for generating a triggering signal 10 which combines request signal 5 and status signal 8 and/or 9 so that information about a possible occurrence or the existence of a rotational motion is taken into account in the decision about triggering the restraining means.
In each of the illustrated exemplary embodiments shown in
In system 1 illustrated in
During an occurring impact situation, request signal 5 is at logic 1. Normally no rollover is predicted so that status signal 8 is at logic 0 and correspondingly inverted status signal 8′ is at logic 1. As long as no rollover is predicted, hold element 13 transfers the state of inverted status signal 8′ directly to downstream AND gate 15. Since a logic 1 is applied to both inputs of AND gate 15, a triggering signal 10 for the requested restraining means is generated.
If a rollover is predicted during an occurring impact situation, status signal 8 is at logic 1 and correspondingly inverted status signal 8′ is at logic 0. This state is sustained by hold element 13 for a defined period of time tstop so that logic 1 and logic 0 are applied to AND gate 15. Only after tstop has elapsed is the then applied instantaneous inverted status signal 8′ which, as mentioned, is normally at logic 1, supplied to AND gate 15. Accordingly, only after expiration of tstop is a triggering signal 10 generated for the requested restraining means.
In system 2 illustrated in
Means 6 described in connection with
It should be noted at this point that the threshold values for the angular positions αx min1 and/or αy min1 and αx min2 and/or αy min2 and the threshold value for the angular velocity ωx min and/or ωy min may not only be determined for each space direction x and y, but also individually for each restraining means. Due to this fact it may be achieved, for example, that triggering of the restraining means in head-on accidents is only blocked when the vehicle has rotated about its x-axis or y-axis by at least 180 degrees. It may be assumed in these cases that the roof has been pushed in and the passenger compartment has become smaller. In contrast, the restraining means assigned to a side impact should be blocked as soon as the vehicle has rotated about its x-axis by at least 90 degrees. The passengers are normally in an unfavorable position in this case so that triggering of a side airbag represents an additional injury risk.
As mentioned earlier, different embodiments 131, 132, 133, and 134 for implementing a hold element are illustrated in
In the embodiment illustrated in
In the embodiment illustrated in
In the embodiments illustrated in
Number | Date | Country | Kind |
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102 18 020.2 | Apr 2002 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/DE03/00780 | 3/12/2003 | WO | 5/6/2005 |