DE102010031123A1 - Method and control device for controlling personal protective equipment for a vehicle - Google Patents

Abstract

A method and a device for controlling personal protection devices for a vehicle are proposed, wherein a minimum force level is detected in the event of an impact and a counter is started at the time of the detection. The activation of the personal protection means is dependent on the meter reading.

Description

State of the art

The invention relates to a method and a control device for controlling personal protection means for a vehicle according to the preamble of the independent claims.

Out EP 1 792 786 A2 a crash box is known which has a housing-like deformation profile with a longitudinal carrier side flange plate and is designed as a folded construction of sheet metal. The deformation profile consists of two shell components, wherein a flange plate portion is integrally formed on each shell component. The shell components are folded out of metal sheet exit plates, then assembled and joined together using resistance welding points. This is a conventional crash box without any adaptation to a crash. However, such an adaptation is for example out DE 197 45 656 A1 known. In this case, an impact damper is proposed for a motor vehicle, wherein a deformation can be controlled as a function of a precrash signal, that is, a signal of a 360 ° view sensor as on a radar sensor or an impact signal. It is proposed that on a deformation element slides move perpendicular to the direction of force and thereby block deformation elements, so that break down by the force effect, these deformation elements by plastic deformation due to the blocking crash energy. By a parallel arrangement or by a disassembly of such deformation elements, an adaptation to the crash process is possible. As another example, it is proposed to use a deformation element through a taper to reduce crash energy. In this case, one element is fixed for rejuvenation and another can be released by a slider to reduce the rejuvenation. The movement of the slide takes place radially, ie perpendicular to the direction of force and thus to the longitudinal axis of the deformation element, usually a cylinder with a predetermined wall thickness.

Disclosure of the invention

The inventive method and the control device according to the invention for controlling personal protection means for a vehicle having the features of the independent claims have the advantage that the inventive method or the control device according to the invention for controlling, for example, crash-active structures, but also of restraints as personal protection are applicable , With the method according to the invention or the control device according to the invention, a very fast control of the personal protection means is possible. By detecting a minimum force level in an impact or at the time of reaching this minimum force level, the inventive method is initiated. Ultimately, the severity of the crash is determined by the meter, and thus the driving decision for the personal protective equipment is made. In this case, a corresponding freewheel is provided, for example, in the crash structure, which is so large that until the complete removal of this freewheel, which expresses itself in a corresponding meter reading, a stop is reached, and then there is a control. The counter is therefore designed so that it will count until it reaches the stop. But also a different orientation of the meter reading for the control of the personal protection means is possible.

In the present case, the activation of the personal protection means means the activation of these personal protection devices, which according to dependent claims can be occupant protection means, but also crash-active structures or other, for example, pedestrian protection means.

The detection of a predetermined minimum force level is the recognition of this minimum force level, d. H. By a sensor device, for example, an acceleration sensor, the achievement of the minimum force level is detected, the acceleration signals, for example, show the breaking of a structure at this minimum force level. As can be seen from the dependent claims, this can be detected, for example, by the breaking of a connecting element, the breaking being detected by the sensor system. This minimum force level is set in such a way that, for example, parking bumps do not lead to reaching this minimum force level.

The counter is in this case carried out electronically, in particular as a software module. It is possible, however, to execute it as a circuit. Any suitable type of counters is possible.

Since the activation of the personal protection device is dependent on the meter reading, this meter reading must be checked. For example, pattern recognition methods, comparators, for example comparators, etc. can be used for this purpose.

A control device is an electrical device that processes sensor signals and generates control signals in response thereto. The interfaces may be formed in hardware or software. The drive circuit may be formed in hardware or software. In particular, it is possible to arrange all software modules on a processor in the control unit. In which Processor can ultimately also be a multi-core processor.

The measures specified in the dependent claims refinements or advantageous improvements of the specified in the independent claims method or control device for controlling personal protection means for a vehicle specified.

Advantageously, the activation of the personal protection means takes place only when the count has reached a predetermined value. This must also be done up to the time when the impact reaches a predetermined stop, d. H. a freewheel, which was planned, is used up until then. For the verification of the meter reading, a comparison is provided which compares the meter reading with a predetermined value. This default value is predefined in experiments. If the value is reached, the control circuit is enabled for control. However, the comparator itself is also released by a release until reached by the impact of the predetermined stop. Also, the comparator and the enable circuit can be designed in hardware and / or software.

It is further advantageous that the control device has a second interface, which may be formed in hardware and / or software, which provides a signal of a sensor that characterizes a load due to the stop by the signal, and that the release circuit in response to the Signal releases the comparator. Accordingly, if the stop is reached, this is detected by the sensor, this generates a signal which in turn is processed by an enable circuit and only if the stop is not reached, is released by the enable circuit of the comparator. For the actuation of the occupant protection means, such as airbags and / or belt tensioners, the drive circuit is caused by other components of the control unit to activate these occupant protection means. In particular, the evaluation of the time difference between reaching the minimum force level and reaching the stop is crucial for this purpose. Data for this time difference are stored in the control unit to determine the severity of the collision. These data can be determined by means of crash tests and / or simulations.

It is furthermore advantageous for crash-active structures to be activated as a function of the meter reading as the first passenger protection device, and for vehicle occupants as second passenger protection means. Thus, the occupant protection can be significantly improved by the invention, since all possible components can be controlled. Advantageously, for the detection of the minimum force level, as indicated above, at least one connecting element is provided in the crash-active structures, which breaks from the minimum force level. This breaking process is detected by the sensors.

Advantageously, the crash-active structures convert crash energy into strain energy by rejuvenating a component of the crash-active structure.

Furthermore, it is advantageous that upon reaching the stop a sensor embodiments are shown in a drawing and are explained in more detail in the following description.

Show it 1 a block diagram of the control device according to the invention with connected components, 2 a flow chart of the method according to the invention, 3 a section of a device according to the invention, the 4 to 6 a respective timeline for different situations and 7 a block diagram of a device according to the invention.

1 shows a block diagram of the control unit SG according to the invention with connected components, wherein in the control unit SG only the necessary blocks for the invention are shown. Other building blocks, which are still necessary for the operation of the control unit SG, but do not serve to understand the invention, have been omitted for the sake of simplicity. A detector D detects directly or indirectly forces acting on the crash structure. It is possible that the detector D itself carries out the evaluation on the achievement of a minimum force level or continuously transmits a signal to the control unit SG and in this control unit SG, the determination of the minimum force level. In the present case, this second case is described. The detector D transmits a corresponding signal to the first interface IF1 of the control unit SG. As will be shown below, the detector D may be, for example, an acceleration sensor or a structure-borne sound sensor which detects, for example, a breakage of a connecting element which will break when the minimum force level occurs as a result of an impact.

The interface IF1 can be formed in hardware and / or software. It can be part of an integrated circuit, but also a single element or just a software element on a microcontroller. The interface IF1 transmits the detection signal of the detector D to a first comparator V1 which compares the detection signal with a value which checks the detection signal for reaching the minimum force level. If this is the case, a counter Z is started depending on the output signal of the first comparator V1. The meter stood is checked by a second comparator V2 and compared with a value, wherein the value is set so that the count counts until reaching a stop due to the impact. This then means a predetermined freewheel. However, the comparator V2 is released by an enable circuit F. This will do the release circuit F until a mounted outside the control unit SG sensor S has detected the reaching of the stop. The signal of the sensor S, for example, an acceleration sensor is transmitted via the second interface IF2, which may be as well as the interface IF1 pronounced transmitted. The second interface IF2 transmits this value to the enable circuit F, the enable circuit F also compares this sensor value with a comparator not shown here, to determine whether the release condition for the second comparator V2 is still satisfied. If the enabled second comparator V2 determines that the predetermined counter reading has been reached, a corresponding signal is forwarded to a drive circuit A which causes the activation of the personal protection means, such as a crash-active structure. All components may be software or hardware.

Alternatively, it is possible that the signal of the detector D is also the enabling circuit F available and the sensor S and the interface IF2 omitted. Other alternatives are possible in the present case.

Since the crash structure is mounted on both sides of the vehicle, one detector D is required per crash structure.

2 shows in a flow chart the flow of the inventive method. In the process step 200 For example, the detector D detects the minimum force level. Depending on this then in the process step 201 the counter started. Depending on the count is in the process step 202 the driving of the personal protection means such as a crash-active structure, but also made as occupant protection means such as airbags or belt tensioners.

3 explains a part of a crash-active structure with which the minimum force level can be detected. In the present case, a front crash structure VC is connected via connecting element VE to a profile EP penetrating as a result of the crash. These fasteners break from a certain minimum level of force. This breakage can be detected. The penetrating profile EP is connected to an adapter plate AP, on which at least one acceleration sensor B is arranged. These acceleration sensors B are able to detect this breaking. Thus, a minimum severity of a collision can be detected, but also the time of reaching this minimum force level can be determined. The crash direction is shown by the arrow F-Crash.

If this minimum force is detected, depending on the Sensierverfahren, including alternative Sensierverfahren compared to 3 , do not know what gravity the collision actually has. It is merely known, but certainly certain, that there will be a collision that has this minimum severity and when that minimum severity has been reached. Based on this information, however, it is not yet possible to decide whether the crash structure should have a high or low absorption capacity or rigidity, that is, whether the stiffness of the crash structure should be adjusted or not. However, this is achieved by the invention.

All constructions to which the invention is applicable must allow an actuator not to be loaded immediately after detecting the minimum severity, otherwise adapting the rigidity will be impossible. The period of time during which the actuator remains unloaded must be known as a function of the speed.

A realization with a short power-free freewheel during the collision shows an example 3 , Shown is a possible relative movement between the components, front crash structure VC and penetrating profile EP. The time t1, at which the actuator is loaded after reaching the minimum severity, results in this case, depending on the collision velocity approximately to:

At this time, the freewheel is used up and the crash force is transmitted through the structure to the actuator located further back. t = 0 here is the achievement of the minimum force level.

A switching of the actuator must take place when the collision speed of a predetermined limit speed, below which the crash structure is to be switched from its initial state to the target state, equal to or less. In this case, the ground state is the highest rigidity, ie it is set by the switching a lower rigidity. The time of loading of the actuator after reaching the minimum severity, at which the switching of the actuator must be completed, results in the case of the limit speed approximately to:

• 1. Die Kollisionsgeschwindigkeit entspricht der Grenzgeschwindigkeit, ab der ein Umschalten auf eine niedrigere Steifigkeit erforderlich ist.
• 2. Die Kollisionsgeschwindigkeit liegt unter der Grenzgeschwindigkeit, ab der ein Umschalten auf eine niedrigere Steifigkeit erforderlich ist.
• 3. Die Kollisionsgeschwindigkeit liegt über der Grenzgeschwindigkeit, ab der ein Umschalten auf eine niedrigere Steifigkeit erforderlich ist.

Since the time .DELTA.t _switching , which requires the actuator to switch to the soft stiffness, is known, can be calculated back from the time t _limit , when no later than a Aktuierungsbefehl must be made. At this time t _Akt according to the invention is in each case a switching of the actuator. Three different cases can be distinguished:

• 1. The collision speed corresponds to the limit speed at which a switch to a lower rigidity is required.
• 2. The collision speed is below the limit speed, from which a switch to a lower rigidity is required.
• 3. The collision speed is above the limit speed, from which a switch to a lower rigidity is required.

v_Grenz:

Kollisionsgeschwindigkeit, unterhalb derer ein Schalten auf eine niedrigere Steifigkeit erfolgt,

t0:

Zeitpunkt des Erreichens der Mindestschwere für eine Energieabsorption

t₁:

Zeitpunkt der Belastung des Aktuators

t_Grenz:

Zeitpunkt der Belastung des Aktuators bei v = v_Grenz

Δt_Schalt:

Zeit, die zum Umschalten erforderlich ist

t_Akt:

Zeitpunkt des Umschaltens

These cases are explained in more detail below, the following applies:

v _limit :

Collision speed below which a shift to a lower stiffness takes place,

t0:

Time of reaching the minimum severity for energy absorption

t ₁ :

Time of loading of the actuator

t _limit :

Time of loading of the actuator at v = v _limit

Δt _switching :

Time required for switching

t _act :

Time of switching

Case 1: The collision speed corresponds to the limit speed at which a switch to a lower rigidity is required.

4 shows the process on a timeline. At t ₀ , the minimum severity for energy absorption of the adaptive crash structure is achieved. At t = t ₁ there is a load of the actuator of the adaptive crash structure, from which a switching of the actuator is no longer possible. It is therefore necessary that the rigidity of the structure is changed before the stop of the two profiles. The time is marked with t _act on the timeline. It is about the switching time Δt _switching before the load of the actuator. If the actuator is actuated at this time, switching is just possible.

Case 2: The collision speed is below the limit speed, from which a switch to a lower rigidity is required.

If the collision speed is below the limit speed, the load of the actuator is only after the time t _limit to the time t ₁ , which is off 5 evident. Based on the assumption that switching at the limit speed is absolutely necessary and carried out at the time t _act , at a lower speed there is sufficient time to switch to a lower rigidity of the structure.

Case 3: The collision speed is above the limit speed, from which a switch to a lower rigidity is required.

If the collision speed is above the limit speed, the time t ₁ , at which the actuator is loaded, is already before the time t _limit , which is off 6 evident. It is switched back to the time t _act .

The time that would be necessary for the Aktuierung, however, is no longer available, since the actuator is already burdened by the crash forces. The actuator thus remains on the hard output stage of the rigidity, which is also desirable according to the high collision speed.

It is thus ensured in all cases that the actuator system provides the correct rigidity for the respective case. The freewheel can also be specifically designed so that is switched directly when reaching the minimum severity (t ₀ = t _act ). In this way, the total actuation time can be minimized.

If, in addition to reaching a minimum force level, it can also be detected by the sensor used that the actuator is loaded, the collision speed can be deduced from the time interval t ₁ -t ₀ . The shorter this time span, the greater the collision speed and thus the collision severity. This can be used to control or adapted trigger different retention means as information.

7 shows the sequence of operations in a block diagram. A sensor 701 in the block 700 constantly monitors the status of the crash structure. If a minimum severity is reached in a collision (t ₀ ) 702 , this will be in a control unit 704 which the data of the sensor 701 evaluates, records. After expiration of the system-dependent period of time is the time t _act from the control unit of the command 705 for the actuation of the adaptive crash structure to the actuators 707 output. Depending on the collision speed is the time t ₁ , at which the actuator 707 is charged. At a high collision speed, the time is earlier, later at a lower collision speed. In 7 this is shown by a dashed double arrow t ₁ . If the collision speed is below the limit speed v _limit , it is possible to switch the actuator from the high to the lower stiffness. The process is completed in this case at time t _limit . If the collision speed is above the _limit , no switching takes place. That is why the double arrow 711 in Aktuatorikfeld, which indicates the Aktuierung between t _act and t _limit , dashed dargstellt. Does it come to a load on the actuator 707 If necessary, this can be sensed via the acoustics monitoring sensor. In the control unit 704 the data are evaluated and used directly for the triggering of restraints 709 or distributed to the corresponding control unit, which controls the retaining means.

The sensing of the actuator load is through 703 characterized and the determination of the actual accident severity by 706 , The variation of the load of the actuator is through 710 as a double arrow (equivalent to t ₁ in the timeline).

The data can be integrated and evaluated in addition to the integration into independent control units, also in a combined control unit. These can also make the actuation of the actuator or generate signals or commands that are transmitted via a bus system to other controllers, which then make an activation of the actuator. It is also conceivable that the data via a bus system z. As a CAN bus, a control unit are sent, wherein the processing and processing of the data takes place in an algorithm. This may be, for example, the airbag control unit. 7 shows an embodiment of the invention.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 1792786 A2 [0002]
• DE 19745656 A1 [0002]

Claims (10)

Method for controlling personal protective equipment (PS) for a vehicle with the following method steps: - Detecting a predetermined minimum force level in an impact and starting a counter (Z) at the time of detection - Control of personal protection (PS) depending on the meter reading. A method according to claim 1, characterized in that the control takes place only when the count has reached a predetermined value, up to the time at which a predetermined stop is achieved by the impact. A method according to claim 2, characterized in that upon reaching the stop a sensor (S) characterizes a load due to the stop by outputting a signal and the control takes place in dependence on the signal. A method according to claim 3, characterized in that as the first personal protection means crash-active structures are controlled in dependence on the meter reading, and that are controlled as the second personal protection means in response to the signal retaining means for vehicle occupants. Control device for controlling personal protective equipment for a vehicle with: - a first interface (IF1) providing a detection signal indicative of reaching a predetermined minimum force level in an impact; A counter which is started at the time of detection of the minimum force level; - A drive circuit (A) which controls the personal protection means in dependence on the count. Control device according to claim 5, characterized in that between the counter (Z) and the drive circuit (A), a comparator (V2) is provided which compares the counter reading with a predetermined value and depending on the comparison, the drive circuit (A) releases to control wherein the comparator is released by an enable circuit (F) until a predetermined stop is reached by the impact. Control unit according to Claim 6, characterized in that the control unit (SG) has a second interface (IF2) which provides a signal to a sensor system (S) which characterizes a load as a result of the stop by the signal, and in that the release circuit (F) in Depending on the signal the comparator (V2) releases. Device with a control device according to one of claims 5 to 7, wherein as first person protection means crash-active structures are controlled in dependence on the count and are controlled as second personal protection means in response to the signal retaining means for vehicle occupants. Apparatus according to claim 8, characterized in that for detecting the minimum force level, the crash-active structures have at least one connecting element that breaks from the minimum force level. Apparatus according to claim 8 or 9, characterized in that the crash-active structures convert crash energies into deformation energy by a taper.

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