Method for controlling restraint devices of a motor vehicle

Abstract

A method for controlling restraint devices of a motor vehicle includes measuring a movement variable of the motor vehicle, triggering a first restraint device on the basis of a first predefined threshold value for the measured movement variable being exceeded, triggering a second restraint device on the basis of a second predefined threshold value for the measured movement variable being exceeded, and activating a first device influencing the restraining force of the first restraint device and a second device influencing the restraining force of the second restraint device on the basis of the first predefined threshold value and/or the second predefined threshold value being exceeded.

Claims

1. A method for controlling restraint devices of a motor vehicle comprising: detecting a movement parameter of the motor vehicle; triggering a first restraint device in response to exceeding a first predetermined threshold value for the detected movement parameter; triggering a second restraint device in response to exceeding a second predetermined threshold value; controlling timers in dependence on a duration of time to thereby activate a first device which influences a restraining force of the first restraint device and a second device which influences a restraining force of the second restraint device in response to exceeding the first predetermined threshold value for the first restraint device and the second predetermined threshold value for the second restraint device, thereby influencing the restraining force of the first restraint device and the restraining force of the second restraint device, such that a sequence in which the first and second restraint devices are triggered is in a fixed succession, in which said fixed succession, the second restraint device is triggered, only if the first restraint device has been triggered earlier in time, said duration of time being determined as a function of a temporal course of the movement parameter and being adjusted or corrected in dependence of a severity of an accident and in dependence of the temporal course of the accident; and adjusting a restraining effect of the first restraint device and the second restraint device according to the severity of the accident, in which, the severity of an actual course of the accident progressively increases with time.

2. The method of claim 1, wherein the duration of time is determined as a function of exceeding a further predetermined threshold value for the movement parameter.

3. A restraint system for a motor vehicle, comprising: at least one crash sensor for detecting a movement parameter of the motor vehicle; a first restraint device; a second restraint device; a first device constructed for influencing a restraining force of the first restraint device; a second device constructed for influencing a restraining force of the second restraint device; and a control device, said control device triggering the first restraint device in response to exceeding a first predetermined threshold value for the detected movement parameter, said control device triggering a second restraint device in response to exceeding a second predetermined threshold value, said control device including timers to control the first and second devices in response to exceeding the first predetermined threshold value, thereby influencing the restraining force of the first restraint device and the restraining force of the second restraint device, such that a sequence in which the first and second restraint devices are triggered is in a fixed succession, in which said fixed succession the second restraint device is triggered, only if the first restraint device has been triggered earlier in time, said duration of time being determined as a function of a temporal course of the movement parameter and being adjusted or corrected in dependence of a severity of an accident and in dependence of the temporal course of the accident, such that a restraining effect of the first restraint device and the second restraint device is adjusted according to the severity of the accident, in which, the severity of an actual course of the accident progressively increases with time.

4. The restraint system of claim 3, wherein the duration of time is a function of exceeding a further predetermined threshold value for the movement parameter.

5. The restraint system of claim 3, wherein the first restraint device includes a seatbelt tensioner and the second restraint device includes an airbag.

6. The restraint system of claim 3, wherein the first restraint device includes a seatbelt limiter and the second restraint device includes a controllable outlet opening of the airbag.

7. A motor vehicle comprising the restraint system of claim 3.

8. The method of claim 1, wherein the detecting of the movement parameter of the vehicle is done with a camera-based sensor, radar sensor, rider sensor, body sound sensor, speed sensor, acceleration sensor, pressure sensor, or any combination thereof.

9. The restraint system of claim 3, wherein the at least one crash sensor for detecting the movement parameter of the vehicle is a camera-based sensor, radar sensor, lidar sensor, body sound sensor, speed sensor, acceleration sensor, pressure sensor, or any combination thereof.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) The present invention is now explained in more detail by way of the included drawings. These show in

(2) FIG. 1 a diagram in which the temporal course of a movement parameter of a motor vehicle is shown and in which the triggering time points of restraint devices and the associated devices are shown according to the state-of-the-art,

(3) FIG. 2 a flow chart, which shows a method for controlling restraint systems of motor vehicle according to the state-of-the-art,

(4) FIG. 3 a diagram in which the temporal course of the movement value of the motor vehicle is shown and the triggering time points of restraint devices and the associated devices is shown, and

(5) FIG. 4 a flow chart of the method according to the invention for controlling restraint devices of a motor vehicle.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

(6) FIG. 1 shows in a diagram 10 the temporal course of a movement parameter a of a motor vehicle according to the state-of-the-art. The curve 12 shows here the course of the movement parameter a in dependence on the time t. The movement parameter a can for example be the speed, acceleration or the longitudinal or transverse acceleration of the motor vehicle. Preferably, the movement parameter a describes the speed, deceleration of a motor vehicle. It is also a measure for the severity of the accident. When the movement parameter a exceeds a first predetermined threshold value a1, the first restraint device is triggered. The first restraint device of the motor vehicle can for example be a seatbelt tensioner. When the movement parameter a of the motor vehicle exceeds a second predetermined threshold value a.sub.2 a second restraint device of the motor vehicle is triggered. The second restraint device of the motor vehicle can for example be an airbag, in particular a front airbag. The triggering of the airbag occurs according to the state-of-the-art in dependence on the exceeding of the threshold value a.sub.2 which has a higher value than the threshold value a1. Thus, the triggering of the seatbelt tensioner occurs always prior to the triggering of the airbag.

(7) Upon reaching the threshold value a.sub.2, the time point t.sub.s2 is simultaneously defined at which the respective timers are started, after the expiration of which the devices for influencing the respective restraining force are triggered. Thus, for example after expiration of a first timer at the time point t.sub.1 a switchable seatbelt limiter is controlled. After expiration of a second time an adaptive airbag vent is for example controlled at the time point t.sub.2. Likewise, after expiration of a further timer at the time point t.sub.n further devices can be triggered which influence the restraining force of the respective restraint device.

(8) FIG. 2 shows a flow chart of a method for controlling restraint devices of a motor vehicle according to the state of the art. Here, it is first tested in a step S10 whether a first predetermined threshold value a1 for the detected parameter a is exceeded. When the predetermined threshold value a1 is exceeded the first restraint device of the motor vehicle is triggered in a step S12, for example a pyrotechnic seatbelt tensioner. In a further step S14 it is now tested whether a second predetermined threshold value a.sub.2 of movement parameter a of the motor vehicle is exceeded. When the threshold value a.sub.2 is not exceeded the method is terminated in step S18. However, when the threshold value a.sub.2 is exceeded, the second restraint device is triggered in a step S16 for example the airbag. In addition, the different timers are started in step S16, which control the triggering of the seatbelt force limiter and the airbag vent.

(9) FIG. 3 shows in a further diagram 16 the temporal course of the movement parameter a in dependence on the time t. Here, the triggering of the restraint devices and the control of the devices, which influence the restraining force of the respective restraint devices is shown according to the method according to the invention. Here, a first restraint device is also triggered after reaching a first threshold value a1. Also a second restraint device is triggered after reaching the second threshold value a.sub.2. The triggering of the first and the second restraint devices can optionally occur in dependence on the exceeding of the first threshold value a1 or the second threshold value a.sub.2.

(10) In the method according to the invention, exceeding the second threshold value a.sub.2 also defines a time point t.sub.s2. In addition, after reaching the first threshold value a.sub.1 a further time point t.sub.s1 is defined. Corresponding time values of the timers after the expiration of which the devices are triggered are not only determined in dependence on the reaching of the time point t.sub.s2 or the threshold value a.sub.2 but also in dependence on reaching the time point t.sub.s1 or the threshold value a.sub.1. Thus for example a first timer is started at the time point .sub.ts1, wherein after expiration of the timer at the time point t.sub.1 the seatbelt tensioner is triggered. It is also conceivable that multiple further timers are triggered at the time point t.sub.s1 which for example expire at the time point tm and trigger a corresponding device which influences the seatbelt tensioner or other restraint devices.

(11) The time points t.sub.1, t.sub.2, t.sub.m and t.sub.n of the respective timers are adjusted in dependence on the severity of the accident. This can occur by way of the temporal course of the movement parameter a. As an alternative a further predetermined threshold value for the movement parameter a can be determined, and wherein the time points t.sub.1, t.sub.2, t.sub.m and t.sub.n are corrected in dependence on this threshold value. The time points t.sub.1, t.sub.2, tm and t.sub.n can now be correspondingly adjusted or corrected in dependence on the severity of the accident and in dependence on the temporal course of the accident. This is shown in FIG. 3 by the arrows 18.

(12) FIG. 4 shows a schematic flow chart 20 of the method according to the invention for controlling restraint devices of a motor vehicle. Here, the method is first started in a step S20 in that a movement parameter a of the motor vehicle is detected. Subsequently it is tested in a step S22 whether a first predetermined threshold value a1 for the movement parameter a is exceeded. In parallel thereto it is tested in a step S24 whether a second predetermined threshold value a.sub.2 for the movement parameter a is exceeded.

(13) If step S22 yields the result that the first predetermined threshold value a1 is not exceeded, the method is continued in step S20 in that it is started anew. However, if it is determined in step S22 that the first predetermined threshold value a.sub.1 is exceed the first restraint device for example the pyrotechnic seatbelt tensioner is triggered in step S26. Also the timer is started in step S26 which causes triggering of the seatbelt limiter.

(14) If it is determined in step S24 that the second predetermined threshold value a.sub.2 of the movement parameter a is not exceeded, the method is continued in step S20 in that it is started anew. If, however, it is determined in step S24 that the second predetermined threshold value a.sub.2 is exceeded, the airbag is triggered in step S28. In addition the timer is started which causes triggering of the adaptive airbag vent.

(15) In a step S30 the further course of the severity of the accident is now tested and the corresponding values for time points t.sub.1 t.sub.2 tm and t.sub.n after expiration of which the respective devices are triggered, are adjusted or corrected by way of the temporal course and/or the severity of the accident. Subsequently it is tested in a step S32 whether at the respective time points t.sub.1, t.sub.2 t.sub.m and t.sub.n the associated values for the timers are reached. If this is not the case the method is continued in step S30. However, if it is determined in step S32 that at the time points t.sub.1, t.sub.2 t.sub.n or tm the respective values for the timers are reached, the respective device which influences the restraining force of the respective restraint device is triggered in step S34. Finally the method is terminated in step S36.

(16) With the method according to the invention, the triggering of restraint devices and the associated devices can occur more reliably in motor vehicles and with this the safety of the vehicle occupants be improved.