EP0862146A2 - Method for recording accident events - Google Patents

Abstract

The system is installed within the road vehicle and has a memory that is used to store dynamic data and status data at the time of an accident. The dynamic data can be in the form of the velocity and acceleration of the vehicle both along the length and width of the vehicle. The status data can include such parameters as engine speed, braking, conditions, warning indicators, etc. The data can be subjected to processing to assign a weighting for the interpretation of the accident.

Description

The invention relates to a method for registering accident events, in particular for use in a vehicle Data registration device which is designed as an accident data memory or the Function of an accident data memory includes.

The purpose of an accident data store is to provide accident-related data register and thereby make it available for later evaluation, so that a The course of the accident can be reconstructed. Data related to the same accident situation belong and thus have a temporal connection an accident event, hereinafter referred to as an event. The concept of accident is to be interpreted broadly because an accident event also includes data from situations should include that suggest a material-damaging driving style to let. An accident in the sense of this invention is therefore every situation that in the normal movement of the vehicle in a potentially harmful manner occurs suddenly and interrupts it if necessary.

Daten" subsumiert werden. Zu den fahrdynamischen Daten zählen die Beschleunigungen des Fahrzeugs in Richtung von dessen Längsachse und Querachse sowie gegebenenfalls von dessen Hochachse. Des weiteren können aus den Beschleunigungen abgeleitete Größen wie der Geschwindigkeitsübertrag, der Ruck, die Leistung oder die Powerrate hinzukommen. Die momentane Fahrzeuggeschwindigkeit wird oft unabhängig von den Beschleunigungen aus dem Signal eines Impulsgebers, der eine Radumdrehung erfaßt, ermittelt. Statussignale geben Auskunft über den Betriebszustand diverser Einrichtungen des Fahrzeugs, ob beispielsweise die Bremse, der Warnblinker oder andere Einrichtungen betätigt worden sind.An accident data memory detects driving dynamics signals and binary status signals, both of which are referred to below for the sake of simplicity

Data "are subsumed. The vehicle dynamics data include the accelerations of the vehicle in the direction of its longitudinal axis and transverse axis and possibly also its vertical axis. Furthermore, variables derived from the accelerations such as the speed transfer, the jerk, the power or the power rate can be added Current vehicle speed is often determined independently of the accelerations from the signal of a pulse generator, which detects a wheel revolution .. Status signals provide information about the operating state of various devices in the vehicle, for example whether the brakes, the hazard lights or other devices have been actuated.

The data to be registered in the accident data memory are displayed in the vehicle suitable locations recorded and sent to the accident data memory. Each Data infeed is hereinafter referred to as a data channel. A Accident data storage usually has a large number of Data channels through which data from various data sources flow to him. The individual data channels are controlled by the control unit of the Accident data storage, usually as a microprocessor or microcontroller is trained, queried at a time interval adapted to practice, whereby the clock rates for the individual data channels are quite different can be different. Driving dynamics data are usually in one faster clock - and therefore more often - in the memory of the Accident data memory read in as status signals.

Conventional accident data storage, such as in EP 0118 818 B1, only evaluate incoming vehicle dynamics data in the With regard to rigid, predetermined limit values. If these are exceeded, the accident data memory evaluates what is characterized by the recorded data Event as an accident. Then all belonging to this event Data is written to a dedicated memory area that this data as a whole remains unchanged until it is evaluated remain. This is precisely when the market demands that a Accident data storage must be able to handle multiple accident events record a relatively large amount of data for which considerable storage means must be made available in the accident data memory. This is however expensive and for the purpose of an accident data storage of only low effectiveness. Because a more differentiated evaluation and storage of the Data does not take place, there is also the disadvantage that such Accident data storage different, due to the vehicle-dependent Operating conditions do not meet the requirements in practice can, because up to now every conventional accident data memory has to be according to his Installation in a vehicle of its respective operating environment individually be adjusted.

It is the object of the present invention, a method for registration of accident events to improve it in that Sensitivity setting to the operating conditions of the accident data memory adapts, especially when it comes to data storage Events with the greatest relevance to an accident considered.

The object is achieved by the features of the first claim. The dependent claims show advantageous configurations and Developments of the found solution.

The solution is characterized by a procedure that involves every event evaluated by a weighting factor and then controlled by evaluation saved. Advantageously, devaluation then no longer takes place relevant events based on defined criteria, as it is in the claims 8 to 12 is shown.

The procedure is as follows: As already described, are the data of all from the control unit of the accident data memory data channels are queried cyclically. Surrender to the Movement data, especially significant with the acceleration data Changes from one to the next data acquisition, these and also other data that is particularly meaningful in relation to an accident situation the occurrence of this change for a predetermined period of time Δt one subjected to close scrutiny. This time period Δt is in the range of Seconds, preferably between 1 and 20 seconds. In addition to Observation of the course of the acceleration data can, for example check whether the brake or the hazard lights have been activated or whether the vehicle has come to a standstill. This test leads to the fact that an event which is characterized by the data recorded in this period Δt is evaluated by an overall view of the recorded data. The review is done by making this event based on that in that period Δt recorded data is provided with a weighting factor. The one The weighting factor assigned to the event consists of a number µ whose Value is between zero and one. One means that an event is greatest It is important, but zero is minor or unimportant Event. The assignment criteria for the number µ to an event can for example in an evaluation of the presence, the intensity, the The duration and the time behavior of data of certain data channels exist. The weighting evaluation of established events in the above Way is the first step in the proposed according to the invention Method. The second step involves the procedure for Storage of the evaluated events, which are now described below becomes.

The data belonging to a certain event is stored in a Event memory belonging to the accident data memory is stored. To this Data is usually added to data immediately before or after the event period Δt were recorded. Because the recording of data from the pre and post event period improves the reconstructibility of the Accident event. It has proven to be practical and useful Data of a continuous period of about 30 to 60 seconds to record if a driving situation as from the accident data memory potential accident event was recognized.

The event memory is designed so that its storage capacity is sufficient for a certain number n of events. For example, it may offer space for n = 10 events. If the control unit of the accident data memory detects a current event with the weighting factor µ ₀ , the event memory is searched for free memory space. If there is enough free space available, the current event and its associated data are saved there. If there is no free memory space, the event with the lowest weighting factor µ = µ _{min is} determined from all events stored in the event memory. A comparison of the weighting factor µ of the current event with the _least significant weighting factor µ _{min of} an event that has already been stored follows. If the weighting factor µ of the current event is at least as large as the weighting factor of the least significant event already saved, i.e. µ _min ≤ µ ₀ , the data of the event with the weighting factor µ _{min is} overwritten by the data of the current event with the weighting factor µ ₀ . If, on the other hand, the weighting factor µ of the current event is smaller than the weighting factor µ _{min of} the _least significant event that has already been saved, that is to say µ ₀ <µ _min , its data are not stored in the event memory.

So that the data of an event with no weighting factor in the Comparison to the events or already stored in the event memory also the data of an event stored in the event memory that is now but should be overwritten, not completely lost, can be in In cooperation with the accident data memory, a statistical memory be provided in which a reduced set of data otherwise available from Loss would be threatened. If necessary, too Events that fall out of the event log after their devaluation, are taken over from the statistics memory. Programming is easier it, basically grasped by everyone, due to significant Changes in measured values detected an event regardless of its weighting to record a reduced data set in the statistical memory, namely even before a decision is made as to whether and in what way the event in the Event log is added. With this latter The data transfer from the event memory to Statistics memory.

The statistics memory is designed so that it is compared to the Event memory can register larger number m of events, whereby for example, m = 100. Its ability to store one Larger number of events also results from the amount of data is reduced per event. So the data recording per event can be limited to a few little information is limited, for example to the time of day Occurrence of the event, the associated mileage of the vehicle and its speed and the original weighting factor µ des Event.

As already mentioned, the statistics memory can also be used in such a way that in principle of each event ascertained in its scope reduced record is stored there, regardless of how this event is handled in the event log. This approach has the advantage that a transfer of data from the event memory in the Statistics memory is never required. Then also lie the data records in the statistics memory always in chronological order, which simplifies their evaluation.

The further, advantageous step of the proposed solution consists in one Devaluation of events in the event log. The one in the event log stored events are continuously checked for their relevance. This check can be carried out by evaluating data channels that are used for a weighting of the value of the events can be considered relevant. In particular, the relevance of an event can be determined by evaluating the Length of the route s to be assessed since the occurrence of the event or by evaluating the residence time ΔT of the individual events in the Event log. Of course, the dependencies mentioned can also are taken into account together, with each also the original weighting factor µ of the event are taken into account can. Which dependencies are appropriate can be determined by practical Considerations are set, with those in the accident data memory Available computing power will certainly be decisive.

In the procedure mentioned, it is assumed that with increasing distance traveled after the occurrence of the event, its relevance continues to decrease after a minimum distance s _min has been exceeded. After this minimum distance s _{min has been} exceeded, the weighting factor μ can be _devalued continuously up to a distance s _max , preferably linearly down to μ = 0. Furthermore, the parameters s _min and s _max can be selected as a function of the original weighting factor, if necessary. Correspondingly, the events can also be devalued on the basis of their dwell time ΔT in the event memory, the original weighting factor μ being continuously, preferably linearly reduced to μ = 0 after a minimum dwell time ΔT _{min has been} exceeded up to a dwell time ΔT _max . The means of the fuzzy logic can then be used to calculate and apply the overall devaluation from all parameters of the devaluation criteria used.

The first two process steps are illustrated in the schematic illustration in FIG. 1 . A reduced data set of all events is stored in a statistical memory belonging to the data registration device. At the same time, the control unit (not shown) of the accident data memory checks whether this event can be stored in the event memory due to its weighting and what effect the storage of this event has on the order of priority of the events already stored there. FIG. 2 shows an example of the procedure for the third method step, which relates to the devaluation of events stored in the event memory. Depending on the original weighting factor µ ₀ , the event is continuously devalued to the value µ = 0 here on the basis of the distance s traveled since it began, which is measured here in km.

The step-by-step procedure for the registration of accident events described here has the particular advantage that the sensitivity of the accident data memory adapts itself adaptively to its particular operating conditions. Due to the devaluation of events in the event memory and the addition of new, current events in connection with the overwriting of old, no longer relevant events, a so-called flow balance is established in the event memory, since after a certain time one of the special operating conditions of the vehicle changes in the event memory dependent evaluation µ _min without factory setting or manual setting on the accident data memory, because only new events with a weighting factor of µ ≥ µ _min are saved, while events with a weighting factor µ <µ _{min are} not recorded in the event memory. This gives the accident data memory the ability to individually adapt its sensitivity to its specific area of application, which considerably improves its usability. A weighting factor of the value µ _min corresponds in each case to the lowest response threshold, which is just still sensible for the vehicle in which the accident data memory is installed, depending on its operating conditions. As a precaution, all situations suspected of accidents are recorded for later evaluation, whereas storing data of little relevance does not impair the functionality of the accident data memory due to an unnecessary use of storage space.

This procedure also helps to register accident events the memory means implemented in the accident data memory are used very effectively. Data of low significance are either immediately discarded or saved only to a limited extent. This means that despite one relatively low total capacity of the storage means nevertheless considerable number of accident events are recorded in good quality. If a statistical memory is implemented, many data records are above one available for a longer period of time, especially when using the Accident data storage in vehicle fleets a certain control and Allow monitoring of the handling of the vehicle. An evaluative Place can take valuable clues from the data in the statistics memory, too if the data records stored there are reduced in scope.

Because of the new storage concept, the data of those always Events are in the foreground that are the most relevant with regard to one Having accidents also increases for the user Accident data memory according to the invention the benefit of data evaluation. Because the amount of data is optimized with regard to its accident relevance.

Claims (12)

Method for registering accident events, in particular for use in a data registration device for vehicles designed as an accident data memory, a) the data registration device continuously recording data, b) where these data are composed dynamic signals generated by the movement of the vehicle, and from binary status signals that indicate a state of vehicle units, c) and data recorded at almost the same time form an accident event if several data in its signal course indicate a sudden deviation from a normal movement sequence of the vehicle,
characterized, d) that each accident event is evaluated in connection with its detection by assigning it a weighting factor, e) that the data belonging to an accident event is only stored if the value of the weighting factor of the currently recorded accident event is at least as large as that of the weighting factors which belong to already registered accident events. A method according to claim 1, characterized in that the evaluation of a current accident event takes place by recognizing a Accident event recorded by the data logger and related to a Accident-relevant data for a specified period of time Δt in your Course can be observed and evaluated and depending on this Observation and evaluation of the accident event caused by this Period Δt recorded data is marked as a number µ Weighting factor is assigned, the value of this number depending on µ the course of the observed in the period Δt and the accident event associated data is between zero and one, with the Weighting factor µ = 1 an accident event of the greatest importance and Weighting factor µ = 0 indicates a minor accident. Method according to claim 2, characterized in that the period Δt to evaluate an accident event in the range between 1 and 20 Seconds. Method according to one of the preceding claims, characterized characterized in that those belonging to a certain accident event Data if necessary together with immediately before or after Period Δt of data recorded in a data registering device Event memory can be saved. Method according to Claim 4, characterized in that the event memory is organized in such a way a) that the control unit of the data registration device first searches it for free storage space as soon as it detects a current accident event with the weighting factor µ ₀ , b) that the current accident event and its associated data are stored there if there is sufficient free storage space available, c) that of all the accident events stored in the event memory, that accident event with the _least significant weighting factor µ _{min is} determined if there is no free memory space available, d) that the weighting factor µ _{0 of} the current accident event is compared with the _least significant weighting factor µ _{min of} an already stored accident event, e) that the data of the accident event with the weighting factor µ _min are overwritten by the data of the current accident event, if the weighting factor µ _{0 of} the current accident event is at least as large as the least significant weighting factor µ _{min of} an already stored accident event, i.e. µ _min ≤ µ ₀ is f) that the current accident event with the weighting factor µ _{0 is} not stored in the event memory if the weighting factor µ _{0 of} the current accident event is smaller than the _least significant weighting factor µ _{min of} an already stored accident event, that is µ ₀ <µ _min . Method according to one of the preceding claims, characterized characterized that of all recognized accident events regardless of their Weighting factors a data set reduced in its amount of data in a statistical memory belonging to the data registration device is stored. Method according to Claim 6, characterized in that the accident events stored in the statistical memory are reduced to the information about: the time of the occurrence of the accident, the associated mileage of the vehicle and its speed and to the weighting factor µ that the accident event received when it was recognized. Method according to one of the preceding claims, characterized characterized in that an accident event stored in the event memory is continuously checked for its relevance by assigning the Weighting factor relevant and from the data logger since entry data and the registration of the accident event be evaluated. A method according to claim 8, characterized in that for the Assessment of the relevance of an accident event the length of the route s since the occurrence of the accident and / or the length of stay ΔT of the Accident event in the event memory are or will be used. Method according to claim 9, characterized in that when assessing the relevance of an accident event based on the length of the driving distance s since the occurrence of the accident event, the original weighting factor µ is continuously reduced to µ = 0 after a minimum distance s _min to a distance s _max has been exceeded : is, the parameters s _min and s _{max being} selectable as a function of the original weighting factor. Method according to claim 9, characterized in that when assessing the relevance of an accident event on the basis of the residence time ΔT of the accident event in the event memory, the original weighting factor µ is continuously reduced to µ = 0 after exceeding a minimum residence time ΔT _min up to a residence time ΔT _max , whereby the parameters ΔT _min and ΔT _max can be selected as a function of the original weighting factor, if necessary. Method according to claims 10 or 11, characterized in that those formed from all parameters of the devaluation criteria used Overall devaluation of the accident events using fuzzy logic is calculated.

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