The invention generally relates to a safety system for vehicle occupants.
In safety systems of the named type, the occurrence of a crash situation is detected using sensors that acquire measurement quantities such as e.g. acceleration and/or pressure. The sensors can be situated centrally in the vehicle or also in its periphery. In particular for the recognition of side crashes, externally positioned sensors are preferably used, which are for example situated in the area of the vehicle doors and which respond to the action of pressure. Vehicles are also increasingly being equipped with satellite-supported navigation systems that enable determination of the location of the vehicle. An essential problem in the controlling of a safety system of this general type, in particular when there is an angular or side collision, lies in the requirement of having to make a decision for the triggering of restraint means, such as air bags, safety belts, and the like, at a very early point in time in the crash process, while at the same time nonetheless achieving a high degree of safety against misuse. In the sense of the present invention, safety against misuse is understood as the capacity of a generic safety system to make a decision to trigger restraint means only if a corresponding risk to the occupants of the vehicle actually exists. The requirement of an early triggering decision results from the fact that in the named types of crashes the vehicle has only a comparatively short crumple zone. A high degree of safety against misuse is required in order to prevent unnecessary triggering of restraint means, because this results in expensive repairs to the safety system.
The present invention offers the advantage that it succeeds in fulfilling the named, conflicting requirements better than has previously been possible. Here the present invention makes use of the recognition that with the aid of data from the navigation system it is possible to determine the location of the vehicle with a high degree of precision. These data are used to evaluate the probability of an angular or side crash, thus enabling an early plausibilization of a triggering decision. If, for example, the vehicle is situated in the area of an intersection, if the output signals of acceleration and/or pressure sensors assume values that indicate a danger, there is good reason to infer that the present event is a side crash. The decision for the triggering of suitable restraint means can thus be plausibilized at an early point in time. On the other hand, an unnecessary triggering of restraint means can largely be prevented with the greatest possible protective function for the vehicle occupants. If, in contrast, in a different situation the data of the navigation system do not contain any indication of an intersection or a junction with a side street, and the vehicle is moving in an orderly fashion in its lane, then the probability of a side crash is to be evaluated as comparatively low. The present invention makes it possible to carry out the plausibilization of a triggering decision in a more differentiated fashion.
In addition, statistical data relating to a particular location, concerning the frequency of accidents at that location, are particularly advantageously taken into account in the triggering decision for restraint means. In this way, the safety system can be made more sensitive at points in the street network having a high frequency of collisions.
Furthermore, current environmental data at the current location of the vehicle can be particularly advantageously acquired and taken into account in the decision for triggering restraint.
The invention will be described in greater detail with reference to the following drawings wherein:
In the following, the principle of the functioning of safety system 1 shown in
If; on the other hand, the vehicle dynamics data supplied by function module 25 and the location data already supplied by function module 26 demonstrate that the vehicle is traveling at an appropriate speed on a street network within the city, perhaps just passing through an intersection, there is a significantly greater risk of a side crash. This greater risk can usefully be taken into account by assigning a greater significance to the output signals of peripheral sensors 24. In practice, this can usefully be achieved in that function module 27 lowers predeterminable threshold values for the output signals of sensors 24, in order to increase their response sensitivity. Particularly advantageously, safety system 21 is also provided, in addition to and linked with the location data supplied by function module 26, with statistical data concerning the frequency of accidents associated with a particular location. In this way, the safety system can for example be switched to be more sensitive when approaching a location known to have a high frequency of accidents. In practice, this can again take place by lowering the threshold values for output signals of sensors 22, 23, 24.
In an advantageous variant embodiment of the present invention, in this connection another function module 200 can additionally be provided that acquires environmental data and evaluates these data. In connection with the location data supplied by function module 26, in this way a still more reliable risk evaluation can take place if necessary. If, for example, a stretch is being traveled that is evaluated as a critical location having high accident frequency with hydroplaning, on the basis of the environmental data supplied by function module 200 it can be verified whether this risk actually exists at the current point in time or not. If it is raining heavily, this risk is to be taken into account as a precaution. If the roadway is dry, on the other hand, it can be assumed that the risk is lower.
Another exemplary embodiment of the present invention is explained on the basis of safety system 30, shown in
Number | Date | Country | Kind |
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10 2004 027 206.9 | Jun 2004 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP05/51843 | 4/25/2005 | WO | 12/1/2006 |