METHOD AND DEVICE IN A MOTOR VEHICLE FOR PROTECTING PEDESTRIANS

Abstract

A method for adjusting at least one trigger criterion of a protection system for the protection of external road users to be protected, especially preferably for the protection of pedestrians, including specifying the trigger criterion for a standard driving situation, ascertaining a longitudinal velocity of the motor vehicle, ascertaining a current or expected transverse movement of the motor vehicle, calculating at least one detection range of at least one environmental sensor for detecting potential collision objects as a function of the longitudinal velocity and the transverse movement, calculating whether collision objects having a predefinable maximum velocity may be struck by the motor vehicle without having previously been detected in the detection range by the environmental sensor, and modifying the trigger criterion to a modified trigger criterion if collision objects may be struck by the motor vehicle without having previously been detected in the detection range by environmental sensor.

Claims

1. A method for adjusting at least one trigger criterion of a protection system the protection of an external road user to be protected in a motor vehicle that includes at least one environmental sensor, the method comprising: a) specifying the trigger criterion for a standard driving situation; b) ascertaining a longitudinal velocity of the motor vehicle; c) ascertaining one of a current or an expected transverse movement of the motor vehicle; d) calculating at least one detection range of at least one environmental sensor for detecting potential collision objects as a function of the longitudinal velocity and the transverse movement; e) calculating whether collision objects having a predefinable maximum velocity may be struck by the motor vehicle without having previously been detected in the detection range by the environmental sensor; and f) modifying the trigger criterion to a modified trigger criterion when step e) indicates that collision objects may be struck by the motor vehicle without having previously been detected in the detection range by the environmental sensor.

2. The method as recited in claim 1, wherein the external road user is a pedestrian.

3. The method as recited in claim 1, wherein for the ascertainment of the transverse movement in step c), at least the longitudinal velocity ascertained in step b) and a steering angle of the motor vehicle are taken into account.

4. The method as recited in claim 1, wherein the trigger criterion in a standard driving situation in step a) encompasses at least two different conditions for detecting a road user to be protected, but the modified trigger criterion has at least one less condition or a condition that is weighted to a lesser degree.

5. The method as recited in claim 1, wherein the trigger criterion in a standard driving situation in step a) encompasses a condition that, prior to a collision, the protection system has identified a road user to be protected, as a collision object with the aid of the environmental sensor, and the condition is not weighted or is weighted to a lesser degree after a modification of the trigger criterion in step f).

6. The method as recited in claim 1, wherein an environment in front of the motor vehicle is subdivided into at least two different detection ranges in step f), and the conditions for detecting a collision object as a road user to be protected is at least one of selected and weighted differently for the different detection ranges.

7. The method as recited in claim 1, wherein the following steps are executed after step f): g) receiving a signal from a contact sensor with regard to a contact of the motor vehicle with a collision object with the aid of at least one contact sensor; and h) outputting a signal for initiating protection measures according to the modified trigger criterion.

8. The method as recited in claim 7, wherein the at least one contact sensor is able to ascertain a location of contact on the motor vehicle, and at least one main contact area having an area width and an area location, in which contact with a road user to be protected is unable to take place without a prior detection by the environmental sensor in the detection range, is ascertained as a function of the longitudinal velocity and the transverse movement of the motor vehicle, so that the trigger criterion for a standard driving situation is maintained for this main contact region despite a transverse movement.

9. The method as recited in claim 8, wherein the main contact area is adapted in at least one of its area width and its area location, as a function of the longitudinal velocity and the transverse movement of the motor vehicle.

10. The method as recited in claim 1, wherein in step c), at least one transverse acceleration of the motor vehicle, detected using at least one acceleration sensor, is taken into account for ascertaining the transverse movement.

11. A device for adjusting at least one trigger criterion of a protection system for external road users for a motor vehicle, the device comprising: a memory medium for the trigger criterion for a standard driving situation; at least one sensor for ascertaining a longitudinal velocity of the motor vehicle; at least one sensor for ascertaining a current or expected transverse movement of the motor vehicle; a calculation unit for calculating a detection range of at least one environmental sensor for detecting potential collision objects as a function of the longitudinal velocity and the transverse movement, and for calculating whether collision objects having a predefinable maximum velocity may be struck by the motor vehicle without having previously been detected in the detection range by the environmental sensor; and a device to modify the trigger criterion to a modified trigger criterion as a function of the result of the calculation in step d).

12. The device as recited in claim 11, wherein the protection system is a pedestrian protection system.

13. A non-transitory machine-readable memory medium on which is stored a computer program for adjusting at least one trigger criterion of a protection system the protection of an external road user to be protected in a motor vehicle that includes at least one environmental sensor, the computer program, when executed by a computer, causing the computer to perform: a) specifying the trigger criterion for a standard driving situation; b) ascertaining a longitudinal velocity of the motor vehicle; c) ascertaining one of a current or an expected transverse movement of the motor vehicle; d) calculating at least one detection range of at least one environmental sensor for detecting potential collision objects as a function of the longitudinal velocity and the transverse movement; e) calculating whether collision objects having a predefinable maximum velocity may be struck by the motor vehicle without having previously been detected in the detection range by the environmental sensor; and f) modifying the trigger criterion to a modified trigger criterion when step e) indicates that collision objects may be struck by the motor vehicle without having previously been detected in the detection range by the environmental sensor.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0051] FIG. 1 shows schematically, a motor vehicle and its environment during cornering.

[0052] FIG. 2 shows the front region of a motor vehicle shortly before the collision with a pedestrian, in a schematized representation.

[0053] FIG. 3 shows a schematized flow diagram to illustrate the sequences in the described method.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

[0054] FIG. 1 shows a motor vehicle 1 on a curved road 19 with a potential driving trajectory 20. Motor vehicle 1 has a protection system 2 for external road users 7 to be protected, who are moving at a predefinable maximum speed V. Using an environmental sensor 3, motor vehicle 1 scans the environment in a detection range S that essentially has the form of a circle segment. In addition, motor vehicle 1 includes a contact sensor (which may also be composed of a plurality of individual sensors) by which the fact of a collision with a pedestrian and also the approximate location of impact are able to be determined. Contact sensor 4 is allocated a main contact area 5 whose area width BB and area position BL in the front area of motor vehicle 1 are able to be designed to be dependent upon the traffic situation. Protection system 2 has a calculation unit 13, which is connected to a first sensor 11 and a second sensor 12. First sensor 11 provides information about longitudinal velocity L of motor vehicle 1, while second sensor 12 provides information pertaining to a transverse movement Q. Transverse movement Q, for example, may depend on a steering angle a (alpha) or also on a drift movement of motor vehicle 1. In the event of a collision with an external road user 7 to be protected, motor vehicle 1 has at least one protection component 6. The triggering of protection component 6 is meant to mitigate the consequences of a collision for road user 7. FIG. 1 shows that external road users 7 to be protected are able to be identified and tracked by detection range S of environmental sensor 3 even during cornering. However, depending on the trajectory of a cornering operation, this does not apply to all potential collision objects 8, in this instance, also to a pedestrian who is intent on crossing road 19. There is the risk that collision object 8 will be struck by motor vehicle 1 in the further course of driving without collision object 8 even having previously appeared in detection range S at all, or without having been in it long enough to allow for a correct identification. It is especially for situations such as this that the protection system is to be configured as a secure and robust system.

[0055] FIG. 2 shows a constellation as it may result in a continued movement of motor vehicle 1 along driving trajectory 20 and collision object 8. Shown is the enlarged frontal region of motor vehicle 1 together with contact sensor 4 and its main contact area 5. In this particular instance, collision object 8 is depicted as a pedestrian who is moving at a maximum speed V and is shown shortly before the collision with motor vehicle 1. Main contact area 5 is set to a relatively narrow area width BB due to the cornering operation of motor vehicle 1, and, as indicated by a dashed line, may also be asymmetrically situated on the vehicle front, especially shifted counter to the direction of the curve. Such an area location BL takes the fact into account that in a left curve, objects on the right side of the road are able to be detected much easier and earlier than those on the left side. Collision object 8 will strike contact sensor 4 outside of main contact area 5 without having previously been identified by the environmental sensor. For this reason, it is advantageous for the protection of this collision object 8 if protection component 6 is triggered as soon as contact sensor 4 responds and also without an identification as a pedestrian having previously been made by environmental sensor 3. If collision object 8 had been a little faster or motor vehicle 1 somewhat slower, then its presence in detection range

[0056] S would have been of sufficient length for an identification and the collision would take place in main contact area 5. In this case, too, protection component 6 would be triggered, but only if a contact with main contact area 5 and an identification as a pedestrian by environmental sensor 3 would have occurred at the same time. However, if a stone or a small animal were to strike main contact area 5 in such a situation, then protection component 6 would not be triggered because no previous identification as a pedestrian has taken place.

[0057] FIG. 3 shows the sequence of the method in protection system 2 in a schematized representation. Data pertaining to longitudinal velocity L of a motor vehicle 1 are supplied to a calculation unit 13 with the aid of a first sensor 11. A second sensor 12 supplies data regarding a transverse movement Q of motor vehicle 1, i.e., initially to a query 9 regarding cornering. If cornering is taking place, then the data are forwarded to calculation unit 13. If no cornering is present, then a trigger criterion A1 for a standard driving situation in a memory medium 10 remains relevant. If cornering is occurring, then calculation unit 13 calculates a current detection range S of environmental sensor 3 and triggers device 14 to modify trigger criterion A1 to a modified trigger criterion A2. Modified trigger criterion A2, too, is able to be stored in memory medium 10. If a collision triggers a signal from contact sensor 4, then there are two possibilities, depending on whether or not the detected contact lies in main contact area 5. A query 16 to main contact area 5 is carried out for this purpose. In the system selected as an example in this instance, area width BB and area location BL of main contact region 5 are specified by a device 15 for modifying main contact area 5, which in turn is actuated by calculation unit 13 as a function of the curve situation. If no cornering is present, then main contact area 5 typically extends across entire contact sensor 4. In the case of a tight curve, area width BB is very small and area location BL may possibly be shifted out of the center of the vehicle front and counter to the curve direction. If query 16 determines that main contact area 5 has been touched, then protection component 6 is triggered via triggering 18 according to trigger criterion A1 for a standard driving situation, both in the case of cornering and straight-ahead driving. If main contact area 5 is not touched, on the other hand, then the triggering of protection component 6 takes place according to modified trigger criterion A2 via triggering 17 for cornering. In other words, triggering takes place even if no pedestrian has been identified by environmental sensor 3.

[0058] Because of the described protection system, external road users to be protected are protected by suitable trigger criteria even in the event of a collision during cornering without significantly increasing the risk of erroneous triggering operations of protection components.