Patent Application
20190248315
The present invention relates to a pre-collision system for an occupant protection system of a vehicle, as well as to an occupant protection system for a vehicle, having such a pre-collision system.
Occupant protection systems that utilize a predictive sensor system or surround sensor system are known from the related art. Sensors, such as radar, ultrasonic or video sensors, for monitoring the surroundings of a vehicle, are used for functions of driver assistance systems and/or occupant protection systems, such as AEB (automatic emergency braking systems). In this context, the object is to acquire environmental data, such as critical objects on a collision course, which are relevant to the specific function. In particular, the optimum conditioning of non-ideal sensor signals is becoming increasing important for reliably detecting and classifying objects in the environment of the vehicle. Currently, further sensor technologies, such as lidar systems, are beginning to be considered and are being developed for future, partially, highly and/or fully automatic driving functions.
At the interface of active and passive safety, so-called pre-crash functions utilize the active safety sensors for monitoring the surroundings, in order to detect a possible collision with a relevant object in a critical situation. In the case of an inevitable collision, on one hand, the activation thresholds of a corresponding air bag control unit can be lowered, in order to optimize the reliability and the robustness of the decision to trigger restraint systems. In addition, reversible “pre-fire functions” for, e.g., controlling a reversible belt tensioner, and/or irreversible “pre-trigger functions” for, e.g., controlling various air bags, adaptive crash structures, pyrotechnically actuated belts, etc., can also be activated as restraining devices for passive safety, in order to lessen the consequences of a collision for the vehicle occupants.
DE 103 45 726 B4 describes, for example, a restraint system for restraining an occupant in a motor vehicle, including a seat belt, to which a force is applied by a belt tensioner connectible to a control unit; at least one vehicle situation detection device for dynamically detecting vehicle situations, the vehicle situation detection device being connectible to the control unit for transmitting the acquired data to the same; and at least one occupant parameter determination device for dynamically acquiring occupant parameter data, the occupant parameter determination device being connectible to the control unit for transmitting the acquired data to it. In a collision phase, the control unit calculates, from the acquired data of the vehicle situation detection device and/or the occupant parameter determination device, the survival space between the occupant and any object the occupant can strike, and correspondingly controls the force of the belt tensioner dynamically for optimum utilization of the survival space in the motor vehicle.
A pre-collision system for an occupant protection system of a vehicle and/or a corresponding occupant protection system for a vehicle, including such a pre-collision system, according to example embodiments of the present invention, have an advantage that a pre-collision system, which provides a lengthened rearward displacement path prior to contact or a collision, can be implemented by expanding a belt tensioning function of a conventional belt system in a simple and cost-effective manner.
Example embodiments of the present invention provide a pre-collision system for an occupant protection system of a vehicle, including a vehicle seat, an evaluation and control unit, and a restraint system. The evaluation and control unit evaluates output signals of the predictive sensor system and activates a belt tensioning function of the restraint system if the evaluation of the output signals indicates an imminent collision. In the belt, the belt tensioning function generates a tensile force, which presses a corresponding occupant into the vehicle seat. In this connection, a kinetic energy or movement of the occupant resulting from the belt tensioning function releases a pre-trigger mechanism, which is integrated into a mounting of the vehicle seat and restores a blocked degree of freedom of the vehicle seat, so that the entire vehicle seat tilts about a defined tilt axis, in the direction of an expected impact force.
According to an example embodiment, an occupant protection system for a vehicle includes a predictive sensor system, a vehicle seat, an evaluation and control unit, a restraint system, and a pre-collision system. In this connection, the evaluation and control unit evaluates output signals of the predictive sensor system and activates a belt tensioning function of the restraint system if the evaluation of the output signals indicates an imminent crash. In the belt, the belt tensioning function generates a tensile force that presses a corresponding occupant into the vehicle seat.
In the case of a head-on collision, example embodiments of the pre-collision system for an occupant protection system of a vehicle reduce the kinetic energy of the occupant on the available restraint path, the so-called ride-down space. If it is possible to successfully give the occupant a preliminary impulse prior to the effect of the impact, then the restraining force can be reduced during the deceleration event. Using the pre-collision protection system having the pre-trigger mechanism, both the restraining path can be increased and the kinetic energy of the occupant can be decreased, which means that the effective restraining force can be reduced in an advantageous manner.
If the belt tensioning function is activated, the occupant rotates with the vehicle seat about the tilt axis, in the direction of the expected impact force, which means that an additional distance and a velocity are generated, which have a positive effect on the loading values of the occupant, since the restraining force can be reduced accordingly. In this connection, the impact force is the force, which acts upon the vehicle due to the collision and causes the vehicle to decelerate. In the frame of reference of the vehicle, an accelerated movement of the occupant is directed oppositely to this force. In addition, the increased inclination of the seat surface counteracts an anti-submarining effect, which relates to unwanted slipping of the occupant under a waist belt. The movement of the occupant and of the vehicle seat advantageously does not require an additional actuator, but is driven via the belt tensioning function alone and activated by the resulting kinetic energy of the occupant moved on the vehicle seat, i.e., of his/her movement.
Presently, the evaluation and control unit can be understood as an electrical device, such as a control unit, in particular, an air bag control unit, which processes and/or evaluates acquired sensor signals. The evaluation and control unit can include at least one interface, which can take the form of hardware and/or software. In a hardware design, the interfaces can, for example, be part of a so-called system ASIC that includes many different functions of the evaluation and control unit. However, it is also possible for the interfaces to be separate integrated circuits or to be at least partially made up of discrete components. In a software design, the interfaces can be software modules that are present, for example, on a microcontroller, next to other software modules. A computer program product having program code, which is stored on a machine-readable medium, such as a solid-state memory, a hard-disk memory or an optical memory, and is used to perform the evaluation when the program is executed by the evaluation and control unit, is also advantageous.
A sensor system or sensor unit is understood as a unit that includes at least one sensor element that measures a physical variable and/or a change in a physical variable directly or indirectly and preferably converts it to an electrical sensor signal. This can be accomplished, for example, by transmitting and/or receiving sonic waves and/or electromagnetic waves, and/or using a magnetic field and/or the change in a magnetic field, and/or by receiving satellite signals, for example, a GPS signal.
Optical sensor elements that include, for example, a photographic plate and/or a fluorescing surface and/or a semiconductor, which detect the incidence and/or the intensity, the wavelength, the frequency, the angle, etc., of the received wave, such as infrared sensor elements, can be used. An acoustic sensor element, such as an ultrasonic sensor element and/or a high-frequency sensor element and/or a radar sensor element, and/or a sensor element, which reacts to a magnetic field, such as a Hall sensor element, and/or a magnetoresistive sensor element and/or an inductive sensor element, which records the change in a magnetic field, e.g., via the voltage generated by magnetic induction, is/are also usable. The sensor signals can be determined statically and/or dynamically. In addition, the sensor signals can be determined continually or one time.
The detected sensor signals are evaluated and converted to sensor data by the evaluation and control unit, the sensor data including a physical variable measured by the specific sensor unit. In this connection, for example, the path change in a specific time window is ascertained by a sensor element, and a speed and/or acceleration is calculated from this by the evaluation and control unit. Further physical variables capable of being calculated include mass, revolutions per unit time, force, energy, and/or other conceivable variables, such as a probability of occurrence of a particular event.
It is particularly advantageous that the pre-trigger mechanism include at least one hinged bearing on which the vehicle seat can be supported so as to be tiltable about the tilt axis. In addition, the pre-trigger mechanism can include at least one rail piece having a guide opening, in which a mounting element of the vehicle seat can be guided between a starting position assumed during normal operation and an end position assumed prior to impact. Preferably, the at least one hinged bearing and the at least one rail piece can be positioned in a seat rail so as to be able to move longitudinally. Thus, for example, the vehicle seat can have, on each side, a seat rail, in which the vehicle seat can be displaced and locked in the longitudinal vehicle direction; each of the seat rails being rigidly connected to the vehicle floor. The system of the present invention can be integrated relatively simply at the seat rails, by replacing the existing connecting elements between the seat assembly, including the seat cushion and seat back, and the seat rails on each side, with, in each instance, a hinged bearing and a rail piece. Then, in the case of such an example embodiment, a hinged bearing and a rail piece are positioned in each seat rail. In this case, the at least one hinged bearing can be situated behind or in front of the at least one rail piece with respect to a vehicle front end. If the hinged bearings are situated behind the rail pieces with respect to the vehicle front end, then the mounting elements move up in the guide opening at the front end of the seat, and the vehicle seat tilts back about the tilt axis situated at the rear end of the seat. If the hinged bearings are situated in front of the rail pieces with respect to the vehicle front end, then the mounting elements move down in the guide opening at the rear end of the seat, and the vehicle seat tilts back about the tilt axis situated at the front end of the seat; the tilting movement being assisted by the gravitational acceleration acting downwards.
In a further advantageous refinement of the pre-collision system, the guide opening can take the form of a slotted hole, which is inclined in the direction of the expected impact force. The maximum additional restraining path can be predetermined by the length of the slotted hole.
In a further advantageous refinement of the pre-collision system, the at least one rail piece can include a locking device that can retain the mounting element in the starting position during normal operation and can release it in response to a detected imminent collision. The locking device can be implemented, for example, as a narrowing of the guide opening running conically inwards. Using this example embodiment, the belt pressure generated by the belt tensioning function can be absorbed gently, as the mounting element deforms the narrowing, which runs conically inwards, during the transition from the starting position to the end position. Alternatively, the locking device can be implemented as a spring element that acts perpendicularly to the longitudinal extension of the guide opening. In this example embodiment, the mounting element can lock into the two positions in a stable manner, after the spring force is overcome. After activation, the seat can easily be pushed back again into the starting position. As a further alternative, the locking device can be constructed as a switchable detent, which frees or blocks the guide opening. In this manner, the pre-collision system can advantageously be prevented from being triggered unintentionally during normal vehicle operation. In addition, the different example embodiments of the locking device can be combined with each other.
Example embodiments of the present invention are depicted in the drawings and are explained in greater detail in the following description. In the drawings, identical reference characters denote components or elements that perform the same or analogous functions.
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For example, a pyrotechnic or electromotive or mechanical actuating system or a pressure reservoir can be used for belt tensioning function GSF.
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In the case of a head-on collision, the kinetic energy of occupant 3 is reduced on an available restraining path, the so-called “ride down space.” Excluding pre-collision system 7 of the present invention, a restraining force FR1 acting upon occupant 3 is yielded from the law of conservation of energy, in accordance with equation (1).
In this case, mI represents a mass, vI_abs represents an absolute velocity of occupant 3, and sR represents an available deceleration path.
Using example embodiments of the pre-collision system 7 according to the present invention, it is possible to successfully give occupant 3 a preliminary impulse prior to the effect of the impact, so that restraining force FR2 is reduced during the deceleration event in accordance with equation (2).
In this case, Av represents a displacement velocity, and Ax represents an additional displacement path. As is further apparent from
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In addition, the different example embodiments 34.2A, 34.2B, 34.2C of locking device 34.2 can be combined with each other.
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Example embodiments of the present invention can advantageously be integrated in the functional landscape and architecture of personal protection systems in a motor vehicle and combined with other occupant protection functions. The decision to use the belt tensioning function is advantageously not made independently of other functions, such as pre-crash positioning, which brings an occupant into an advantageous position prior to a collision, or individual occupant sensing, which determines the current position of the individual occupants, but is made in a coordinated manner.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102016213071.4 | Jul 2016 | DE | national |
The present application is the national stage of International Pat. App. No. PCT/EP2017/065029 filed Jun. 20, 2017, and claims priority under 35 U.S.C. § 119 to DE 10 2016 213 071.4, filed in the Federal Republic of Germany on Jul. 18, 2016, the content of each of which are incorporated herein by reference in their entireties.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2017/065029 | 6/20/2017 | WO | 00 |
