DE102005005959B4 - Device and method for controlling a safety device of a vehicle - Google Patents

Abstract

Device for controlling a safety device (18) of a vehicle, having a precrash sensor (10) which has a plurality of separately evaluable detection regions (22, 23, 24) for detecting collision objects (12, 14) and a control unit (16) for Controlling the safety device (18), wherein the control unit (16) is designed to assign object classes and collision objects (12, 14) due to characteristic features in a signal waveform measured by the pre-crash sensor (120) and the triggering time (s) and / or tripping intensity (s) of one or more protection means (20) of the safety device (18) depending on the assigned object classes set characterized in that the control unit (16) is adapted to in several detection areas (22, 23, 24) of the precrash sensor (10) collision objects (12) detected the distance values determined for each detection area (22, 23, 24) and the Kollisi classify objects as an object (12) if the determined distance values lie within a predetermined tolerance range.

Description

The invention relates to a device for controlling a safety device of a vehicle according to the preamble of claim 1 and a corresponding method according to the preamble of claim 20.

For controlling a vehicle safety device such as an occupant protection system, the signals from acceleration sensors are evaluated by being compared with one or more predetermined threshold values. When the threshold values are exceeded, triggering signals are generated for protective means such as, for example, airbags or belt tensioners. However, there is only a short period of time between the detection of a crash-relevant acceleration of the vehicle and the formation of a trigger signal, usually a few milliseconds, which often makes it difficult or even impossible to distinguish between different crash scenarios with different triggering requirements.

In order to be able to better adapt the triggering of protection means to an accident scenario and thus to achieve a more efficient use of protection means, the relative speed measured between a vehicle and the collision object, for example by means of a precrash sensor, can be evaluated and used to adapt triggering thresholds of protection means. Further improvement of the safety device efficiency can be achieved by classifying collision objects and adapting the use of protection means accordingly. For example, this describes EP 1 409 296 B1 a method that classifies objects based on acceleration signals derived from precrash sensor data and their time derivative. From the WO 2004/033260 A1 In addition, a device is known in which the triggering of a second airbag stage of a multi-stage airbag takes place as a function of the acceleration and a measured impact speed. A more detailed classification is from the DE 102 35 164 A1 which describes a method which can detect a collision with a pole from the signal profiles of a precrash sensor and acceleration sensors.

A particularly accurate classification of collision objects can be achieved, for example, with a camera and corresponding image processing. However, such a solution is technically very complicated and therefore expensive. A low-cost precrash sensor does not have the required resolution for such a precise classification and is therefore not suitable as a camera replacement.

Further methods for object classification are described in the following documents.

The DE 102 43 397 A1 presents a distance sensor combined with an image sensor for detecting potential collision objects. Distances, distance changes and contrast difference images are evaluated to detect obstacles and their type of hazard and potential.

The DE 102 31 362 A1 discloses an environment monitoring device in a vehicle that selects objects in the detection area and keeps track of only those objects. This should allow the adaptive use of reversible restraints.

The DE 102 02 908 A1 introduces a precrash sensor system to detect potential accidents. For this purpose, an object detected by the sensor system is classified and the determined object class is taken into account when setting safety devices.

The DE 103 42 045 A1 shows a device for environment detection by an alternating magnetic field. An object in the vehicle environment causes a second alternating magnetic field as a function of the first alternating field.

In the DE 103 35 601 A1 describes a method of object classification using a 3D model database. To recognize surrounding objects, video images are taken and compared with stored data models. This also varies the 3-D position of the model in the room.

Also the DE 103 24 217 A1 has the classification of at least one object with an environment sensor to the object. The object class is determined by the velocity and the acceleration of the detected object.

The DE 100 65 518 A1 discloses a method for triggering restraint means in a vehicle. Here is a classification of the detected environmental object in terms of its mass and rigidity intended. The object of the present invention is now to propose an apparatus and a method for controlling a safety device of a vehicle, which enable a classification of collision objects by means of a precrash sensor.

This object is achieved by a device for controlling a safety device of a vehicle having the features of claim 1 and by a corresponding method having the features of claim 20. Preferred embodiments of the invention will become apparent from the dependent claims.

An essential idea of the invention is to assign objects based on characteristic features in a signal course measured by a precrash sensor to certain object classes and to set the triggering time and / or triggering intensity of one or more protection means of a security device depending on the assigned object classes.

The invention now specifically relates to a device for controlling a safety device of a vehicle, having a precrash sensor which has a plurality of separately evaluable detection areas, for detecting collision objects and a control unit for controlling the safety device. The control unit is designed to assign object classes to collision objects based on characteristic features in a signal course measured by the precrash sensor and to set the triggering time and / or triggering intensity of one or more protection means of the security device depending on the assigned object classes.

A further essential feature of the invention is to compare the distance values determined for each detection area in several detection areas of the pre-crash sensor with each other and to classify the collision objects as an object if the determined distance values are within a predetermined tolerance range.

Preferably, the precrash sensor has three separately evaluable detection areas, for each of which a distance value between a collision object detected in the respective detection area and the vehicle can be determined. It has been shown that with three detection areas a sufficiently accurate classification of collision objects is possible with a relatively low technical outlay.

In particular, distance ranges may be defined for the object classes and detection areas in which a detection of a collision object is expected.

The object classes can be selected depending on the geometry of the detection areas and relevant collision objects.

Furthermore, the control unit can be designed to set an object indicator for one or more object classes in a collision object detected in a specific combination of detection areas and in a specific distance range.

Instead of distance ranges, probability functions can also be defined for each object class, which have the determined distance value of a collision object and the combination of the recording areas as input variables and the recognition probability of the respective object class as output variable.

Furthermore, the control unit can be designed to subject object indicators and / or recognition probabilities to qualification, integration and / or filtering in order to achieve the most accurate classification result possible.

The control unit can also be designed to compare the individual assigned object classes with respect to their quality index, integral or filter output at the time of an actual collision and / or in a definable time or distance window and to select and output the most probable object class as relevant.

Typically, the object classes include an approximately frontal collision with a pole and a wall, a collision with a wall at an oblique angle, and a collision with a laterally offset obstacle.

In addition to the object classes, a separate class may be provided that includes objects having a distance that is shorter than an outside dimension of a vehicle. Such objects can z. B. a truck (truck) -Unterfahrten or vehicle-pedestrian collisions, in which the upper body or head of the pedestrian is already partially over the hood of a vehicle.

The control unit can also be designed to monitor one or more criteria which prevent the assignment of an object class to a collision object in the event of insufficient statement reliability. This increases the security against misclassification.

A criterion can be used as a possible criterion z. B. include a minimum value of a relevant object class and / or a minimum difference of a relevant to all other object classes.

In a preferred embodiment, the control unit is designed to take into account a limited selectivity between the detection areas of the precrash sensor when assigning a collision object to an object class. This can increase the accuracy of the classification.

Furthermore, the control unit can be designed to take into account a tolerance of a measured distance of a collision object in the assignment of the collision object to an object class, whereby the accuracy of the classification can likewise be increased.

In the control unit, a parameter can be stored, which is adjustable to the distance in which a collision between the vehicle and collision object is to be expected. This distance may be, for example, the distance between the precrash sensor and a central location of the bumper of the vehicle.

Preferably, the distance is adjustable as a function of the angle at which a potential collision object can be detected by one or more crash sensors. As a result, different collision distances can be taken into account, for example, for straight and oblique collisions, which result from the geometry of the bumper or the vehicle.

The control unit can also be designed to use an object class assigned to a collision object and / or an orientation of the capturing detection area for the selection of further data of the precrash sensor.

The precrash sensor can operate on the principle of a radar, laser or ultrasonic sensor, whereby a transit time and / or frequency / phase shift between an emitted and a received signal is detected.

Finally, the control unit can be designed such that the triggering time and / or tripping intensity is advanced or increased by one or more guard devices of an object class with a low initial acceleration in the event of a collision, such as a central pole or a deformable barrier, and with an object class a high initial acceleration in case of collision such as a wall is delayed or attenuated or the triggering is completely suppressed depending on further criteria.

The invention further relates to a method for controlling a safety device of a vehicle, in which a pre-crash sensor, which has a plurality of separately evaluable detection areas, detects collision objects. Due to characteristic features in a signal course measured by the pre-crash sensor, the collision objects are assigned specific object classes and the triggering time and / or triggering intensity are set by one or more protection means of the security device depending on the assigned object classes. In addition, in the case of collision objects detected in a plurality of detection regions of the pre-crash sensor, the method provides for comparing the distance values determined for each detection range and classifying the collision objects as an object if the determined distance values lie within a predetermined tolerance range. The tolerance range can be determined empirically, for example.

Further advantages and possible applications of the present invention will become apparent from the following description in conjunction with the embodiments illustrated in the drawings.

In the description, in the claims, in the abstract and in the drawings, the terms and associated reference numerals used in the list of reference numerals recited below are used.

The drawings show in:

1 in a plan view, the detection of a frontal collision with a wall by a precrash sensor with three detection areas;

2 in a plan view, the detection of a frontal collision with a pile by a pre-crash sensor with three detection areas;

3 in a plan view, the detection of a collision with a wall at an oblique angle by a pre-crash sensor with three detection areas;

4 in a plan view, the detection of various collisions with a laterally offset to the longitudinal axis of a vehicle pole (a) and b)) and with a laterally offset to the longitudinal axis of a vehicle wall (c) and d)) by a precrash sensor with three detection areas;

5 in a plan view, the detection of a collision with an already penetrated into the vehicle structure pile (a)) and an already penetrated into the vehicle structure wall (b)) by a pre-crash sensor with three detection areas; and

6 a vehicle with a device for controlling a safety device according to the invention.

In the following, identical and / or functionally identical elements can be provided with the same reference numerals.

1 shows in plan view a detection of a frontal collision with a wall 12 through a precrash sensor, which has a first, right detection area 22 , a second, left detection area 24 and a third, middle, that is arranged between the first and second detection area detection area 23 having. The three coverage areas 22 . 23 and 24 can overlap, which affects the selectivity between the detection areas of the precrash sensor. The precrash sensor can be used to detect whether and at what distance from the precrash sensor a collision object is located.

In 1 is a wall as a collision object 12 shown approaching the front of a vehicle with the precrash sensor. The wall 12 will be in all three coverage areas 22 . 23 and 24 detected at approximately the same distance. As a result, an unillustrated control unit arranges the signals in the three detection ranges by corresponding processing of the signal course measured by the precrash sensor 22 . 23 and 24 detected objects a single, wide collision object 12 to.

In 2 is a frontal collision with a pole 14 shown as a collision object. Here is only in the middle coverage area 23 a collision object detected. Therefore, due to the corresponding signal curve measured by the precrash sensor, the control unit arranges that in the detection area 23 detected object as a single narrow collision object such as a pole or a tree.

3 shows a collision with a wall 12 at an angle. This will be back in each of the three coverage areas 22 . 23 and 24 each detected an object, but each with different distances. In the left in 3 The scenario presented is in the coverage area 22 an object at a distance d1 detected in the detection area 23 an object at distance d2 and in the detection area 24 an object at distance d3. The following applies for the distances: q1 <d2 <d3. The control unit now processes the signal curve measured by the precrash sensor by first comparing the measured distances with one another. If the measured distances lie within a predetermined distance range or have values as explained above, it can be assumed with high probability that three objects become a single collision object 12 belong. Due to the distances d1 and d3, the control unit can also determine the angle at which the collision object is located 12 ie the wall approaches the precrash sensor. Such information is used in the control unit to set the trip time (s) and tripping intensity (s) of protection means such as airbags. For example, the deployment of an airbag in the event of a collision with a wall 12 , as in 3 indicated, delayed in time and attenuated the intensity, for example, by the gas generator is controlled accordingly for the airbag.

4 shows collisions with laterally to the longitudinal axis of the precrash sensor and thus of the vehicle in which the precrash sensor is arranged, offset collision objects. In 4a) and b) is a stake 14 as a collision object so laterally offset that it is in the first, right and second, left detection area 22 respectively. 24 of the precrash sensor is located. The control unit therefore classifies the pile as a narrow collision object that is laterally offset. In 4c) and d) is another vehicle 12 is laterally offset as a collision object and is used by the precrash sensor in the first, right and middle detection areas 22 and 23 ( 4c) ) or in the second, left and middle detection area 24 and 23 ( 4d) ) detected. Due to the same distance in both detection areas 22 and 23 respectively. 24 and 23 becomes the other vehicle 12 classified as a single collision object that is laterally offset. The classification can again be used to adjust the triggering of a protection means, for example by triggering protection means on the side of the vehicle early and with high intensity, on which the collision object is located.

Finally shows 5 another stake 14 ( 5a) ) or a structure of another vehicle 12 ( 5b) ) as a collision object, the or already in the structure of a vehicle 26 has penetrated or is located above the structure of a vehicle. Even in such cases, the pre-crash sensor can still provide evaluable information for the use of protection means, for example, in which direction the collision object moves when penetrating into the vehicle structure, as well as the time and depth of penetration or overlapping.

6 shows a vehicle 26 in side view with a schematically illustrated device for controlling a safety device 18 that has a precrash sensor 10 , which is mounted in the area of the rearview mirror in the vehicle interior and detects the area in front of the vehicle, and a control unit 16 for controlling the safety device, in the present case an airbag system with an airbag 20 includes.

The control unit not only receives a signal from the pre-crash sensor 10 for evaluating and corresponding control of the airbag, but also, for example, from a crash sensor 28 in the area of the bumper, which directly detects a crash. The control unit comprises further acceleration sensors 30 for crash detection, preferably in the vicinity of the vehicle's center of gravity.

In the following, an exemplary embodiment of the assignment of collision objects to object classes is illustrated by means of the signal course measured by the precrash sensor, as for example according to the invention by an algorithm implemented in the control unit for evaluating and processing the signal course measured by the precrash sensor can be made: object class collision object waveform 1 Pile frontal (Fig. 2) Collision object in the detection area 23 detected; a single narrow collision object 2 Wall frontal (Fig. 1) Collision object in the detection area 22 . 23 and 24 detected; Measured distances in the detection areas are within suitable tolerances to each other, therefore, a single wide collision object 3a, 3b Wall at an oblique angle (Fig. 3) Collision object in the detection area 22 . 23 and 24 detected; Measured distances in the detection areas are different, but decrease from left to right or vice versa, therefore, with high probability, a single wide collision object at an oblique angle; Angle approximately by measured distances in the outer detection areas 22 and 24 determinable 4a, 4b Pile laterally offset (FIG. 4a), b)) Collision object in the detection area 22 respectively. 24 detected; a single narrow collision object, offset laterally to the precrash sensor longitudinal axis 5a, 5b Wall or vehicle laterally offset (Figure 4c), d)) Collision object in the detection areas 22 and 23 respectively. 23 and 24 detected; measured slightly equal distances in the detection areas, therefore, a single wide collision object, laterally offset from the precrash sensor longitudinal axis 6 Stake in vehicle structure already penetrated (FIG. 5a)) In all three coverage areas 22 . 23 and 24 Collision object detected, with approximately the same distance, very close to the precrash sensor, therefore a single collision object that has already penetrated into vehicle structure 7 Object in vehicle structure already penetrated (Fig. 5b)) or above it In all three coverage areas 22 . 23 and 24 Collision object detected, with approximately the same distance, very close to the precrash sensor, therefore a single collision object that has already penetrated into vehicle structure or is located above it

For each object class can now turn in the control unit a certain deployment plan for protection means such as airbags, belt tensioners or the like may be provided. For example, it may be specified that side airbags arranged on the right or left in the vehicle in the class of objects 4a or 4b are triggered prematurely with high intensity and the side airbags on the left or right in the vehicle are not triggered. For the object class 5a and 5b, it may be specified that belt tensioners are activated immediately and all airbags present in the front region of the vehicle immediately with high intensity.

The invention thus makes possible a far more flexible and better adapted to an accident use of protection means using a low-cost precrash sensor.

LIST OF REFERENCE NUMBERS

10

Precrash sensor with three detection ranges

12

Collision object wall or vehicle

14

Collision object pile

16

Control unit for controlling a safety device

18

Airbag Safety System

20

air bag

22

first, right detection area of the precrash sensor 10

23

third, middle detection range of the precrash sensor 10

24

second, left detection area of the precrash sensor 10

26

vehicle

28

crash sensor

30

accelerometers

Claims (20)

Device for controlling a security device ( 18 ) of a vehicle, with a precrash sensor ( 10 ), which contains several separately evaluable detection areas ( 22 . 23 . 24 ), for the detection of collision objects ( 12 . 14 ) and a control unit ( 16 ) for controlling the security device ( 18 ), the control unit ( 16 ) is designed to collision objects ( 12 . 14 ) due to characteristic features in one of the precrash sensor ( 120 ) assigned to certain object classes and the triggering time (s) and / or tripping intensity (s) of one or more protection means ( 20 ) of the security device ( 18 ) depending on the assigned object classes, characterized in that the control unit ( 16 ) is designed to be used in several detection areas ( 22 . 23 . 24 ) of the precrash sensor ( 10 ) detected collision objects ( 12 ) for each coverage area ( 22 . 23 . 24 ) and the collision objects as an object ( 12 ), if the determined distance values lie within a predetermined tolerance range. Apparatus according to claim 1, characterized in that the precrash sensor ( 10 ) three separately evaluable detection areas ( 22 . 23 . 24 ), for each of which a distance value between one in the respective coverage area ( 22 . 23 . 24 ) collision object ( 12 . 14 ) and the vehicle ( 26 ) can be determined. Apparatus according to claim 1 or 2, characterized in that for the object classes and detection areas ( 22 . 23 . 24 ) Distance ranges are defined in which a detection of a collision object ( 12 . 14 ) is expected. Apparatus according to claim 3, characterized in that the object classes depending on the geometry of the detection areas ( 22 . 23 . 24 ) and relevant collision objects ( 12 . 14 ) are selected. Device according to claim 3 or 4, characterized in that the control unit ( 16 ) is designed to be used in a particular combination of detection areas ( 22 . 23 . 24 ) and in a certain distance range detected collision object ( 12 . 14 ) set an object indicator for one or more object classes. Device according to claim 1 or 2, characterized in that for each object class probability functions are defined, which determine the determined distance value of a collision object ( 12 . 14 ) and the combination of the coverage areas ( 22 . 23 . 24 ) as input variables and the recognition probability of the respective object class as output variable. Device according to one of the preceding claims, characterized in that the control unit ( 16 ) is configured to subject object indicators and / or recognition probabilities to qualification, integration and / or filtering. Device according to claim 7, characterized in that the control unit ( 16 ) is adapted to compare the individual associated object classes in terms of their quality index, integral or filter output at the time of an actual collision and / or in a definable time or distance window and to select and output the most probable object class as relevant. Device according to one of the preceding claims, characterized in that the object classes comprise an approximately frontal collision with a pole and a wall, a collision with a wall at an oblique angle and a collision with a laterally offset obstacle. Apparatus according to claim 9, characterized in that in addition to the object classes a class is provided which comprises objects having a distance which is shorter than an outer dimension of a vehicle. Device according to one of the preceding claims, characterized in that the control unit ( 16 ) is configured to monitor one or more criteria that determine the association of an object class with a collision object ( 12 . 14 ) with an insufficient statement security. Apparatus according to claim 11, characterized in that a criterion comprises a minimum value of a relevant object class and / or a minimum difference of a relevant to all other object classes. Device according to one of the preceding claims, characterized in that the control unit ( 16 ) is designed to provide a limited selectivity between the detection areas ( 22 . 23 . 24 ) of the precrash sensor ( 10 ) when assigning a collision object ( 12 . 14 ) to consider an object class. Device according to one of the preceding claims, characterized in that the control unit ( 16 ) is adapted to a tolerance of a measured distance of a collision object ( 12 . 14 ) when assigning the collision object ( 12 . 14 ) to consider an object class. Device according to one of the preceding claims, characterized in that in the control unit ( 16 ) a parameter is stored which is based on the distance in which a collision between the vehicle ( 26 ) and collision object ( 12 . 14 ) is to be set is adjustable. Apparatus according to claim 15, characterized in that the distance is adjustable as a function of the angle at which a potential collision object ( 12 . 14 ) of one or more crash sensors ( 28 ) can be detected. Device according to one of the preceding claims, characterized in that the control unit ( 16 ) is adapted to a collision object ( 12 . 14 ) associated object class and / or an orientation of the detecting coverage area ( 22 . 23 . 24 ) for the selection of further data of the precrash sensor ( 10 ) to use. Device according to one of the preceding claims, characterized in that the precrash sensor operates on the principle of a radar, laser or ultrasonic sensor, wherein a transit time and / or frequency / phase shift between an emitted and a received signal is detected. Device according to one of the preceding claims, characterized in that the control unit ( 16 ) is designed such that the triggering time and / or tripping intensity of one or more protection means ( 20 ) of the security device ( 18 ) at an object class with a low initial acceleration in the event of a collision such as a central pole or a deformable barrier is advanced or delayed in a class of objects with a high initial acceleration in case of collision like a wall or the triggering depending on other criteria entirely is suppressed. Method for controlling a security device ( 18 ) of a vehicle in which a precrash sensor ( 10 ), which contains several separately evaluable detection areas ( 22 . 23 . 24 ), collision objects ( 12 . 14 ), wherein the collision objects ( 12 . 14 ) due to characteristic features in one of the precrash sensor ( 10 ) are assigned to certain object classes and the triggering time (s) and / or triggering intensity (s) of one or more protection means ( 20 ) of the security device ( 18 ) are set as a function of the assigned object classes, characterized in that, in the case of several detection areas ( 22 . 23 . 24 ) of the precrash sensor ( 10 ) detected collision objects ( 12 ) for each coverage area ( 22 . 23 . 24 ) and the collision objects as an object ( 12 ), if the determined distance values are within a predetermined tolerance range.

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