Method for triggering a restraining means and child restraint device having the restraining means - Patents.com

Abstract

The invention relates to a method for triggering protective means, in particular an airbag and / or a belt tensioner, in a child restraint device, in particular according to one of claims 18 to 20, comprising the steps of a) determining at least one measurement direction and / or one measurement direction corridor, b) receiving acceleration sensor signals from at least two acceleration sensors (74x, 74y, 74z), preferably oriented in different directions, c) calculating at least one first acceleration value (aX) along the measurement direction and / or in the measurement direction corridor, d) determining a trigger signal based on the at least one first acceleration value (aX) and e) triggering the at least one protective means based on the trigger signal.

Description

Detailed Description of the Invention

[0001] The present invention relates to a child restraint device for mounting in a vehicle seat, in particular a child seat and / or an impact shield, comprising at least one (active) restraint means, and a method for triggering (activating) the restraint means.

[0002] DE 4 418 028 A1 describes a child car seat with an impact shield, which is equipped with an airbag, which is arranged in the upper section of the impact shield in order to protect the head of a child sitting in the child car seat (in the event of an impact).

[0003] DE 20 2017 105 118 U1 also discloses a child car seat with an impact shield. According to the state of the art, the airbag can be arranged in various positions, for example in the upper or lower section of the impact shield or in the center of the impact shield, in order to spread the upper and lower sections away from each other. Furthermore, DE 20 2017 105 118 U1 describes a child car seat with a protection means in the form of a belt system that can close when a certain acceleration value is exceeded.

[0004] DE 10 2017 126 235 A1 describes a child car seat with an impact shield having an airbag, which is arranged either in the lower compartment or in the rear compartment (facing the child sitting in the child car seat).

[0005] DE 19 722 095 C1 describes a child car seat with a support bracket in which an airbag is placed. When triggered, the gas bag of the airbag expands. This should occur in as controlled a manner as possible.

[0006] DE 4 418 028 B4 shows various ways of arranging airbags on child seats: the gas generator is in each case arranged immediately next to the gas bag.

[0007] US 5 375 908 A shows a child car seat with an airbag, in which a gas generator is arranged in the seat compartment of the child car seat.

[0008] DE 19 534 126 C1 describes a gas cartridge that is integrated into the seat part of a child car seat and supplies the airbag via a pressurized line.

[0009] EP 1 452 386 B1 describes an airbag in a chest pad, which is arranged in a hollow housing.

[0010] US Pat. No. 6,736,455 B1 describes an airbag which, in its initial state, is arranged below a cushion-like compartment.

[0011] A child car seat with active protection means (e.g. an airbag) is known from EP 2911910 B1, in which the airbag is triggered only if both the use of the child car seat and an accident situation are detected, the accident situation being detected by a detection means having both mechanical and electronic means.

[0012] A child car seat with active protection means (e.g. an airbag) is known from EP 2911910 B1, in which the airbag is triggered only if the acceleration of the child car seat exceeds a first threshold within a first time interval and a second threshold within a second time interval, the second time interval being encompassed within the first time interval and the second threshold being greater than the first threshold.

[0013] EP 3406481 B1 describes a child car seat comprising a seat and a seat base and having active protection means (e.g. an airbag), which cannot be triggered while the inclination of the seat pan is adjusted relative to the seat base.

[0014] So far, various solutions with active protection means for child seats (especially airbag solutions) have not been able to dominate the market, possibly due to requirements that can be difficult to comply with, such as: - The safe and reliable use of the protective measures (in particular the avoidance or at least reduction of any risks that could arise from the airbag alone). - The additional effort is acceptable to the user. - It can be easily used.

[0015] Trigger control in particular poses a problem because standard child car seats are not connected to the vehicle's electrical system, meaning the car seat needs its own reliable power source and its control system often does not have access to the vehicle's many available sensor information.

[0016] It is therefore an object of the present invention to provide a child restraint device having a protective means and a corresponding method for triggering the protective means that overcomes the problems of the prior art. In particular, the device and method should be safe, easy to operate, and provide reliable triggering.

[0017] This object is solved in particular by the features of claim 1.

[0018] In particular, the object is to provide a method for triggering a restraining means in a child restraint system in a vehicle, the method comprising: a) determining at least one measurement direction and / or measurement direction corridor; b) receiving acceleration sensor signals from at least two acceleration sensors, preferably oriented in different directions; c) calculating at least one first acceleration value along the measurement direction and / or within the measurement direction corridor; d) determining a trigger signal based on at least the at least one first acceleration value; e) triggering active protection measures based on the trigger signal; The problem is solved by a method including:

[0019] Thus, one embodiment of the present invention is based on the use and evaluation of several acceleration sensors, and for a particular embodiment, preferably acceleration components acting in a particular direction, i.e., measurement direction, and / or lying within a particular measurement direction corridor are taken into account. The measurement direction corridor can be, for example, a volume, such as a cone, that is rotationally symmetric about the measurement direction, or an angular range around the measurement direction. The measurement direction corridor can also be specified by a plane or a vector.

[0020] At least, determining the trigger signal based on the at least one first acceleration value can include direct and indirect determination of the trigger signal. For example, the acceleration value can be used to detect the presence of a precondition for providing the trigger signal. The direct criteria for providing the trigger signal can optionally be determined based on other signals or values, for example, using an acceleration sensor signal. In one embodiment, a warning mode is employed based on the at least one first acceleration value.

[0021] The acceleration sensors are preferably acceleration sensors oriented in different directions. Such acceleration sensors are often combined into a unit, for example an acceleration sensor unit. In one embodiment, an acceleration sensor unit is used that measures acceleration values ​​on at least two axes, preferably three axes. Preferably, the axes used can be perpendicular to each other.

[0022] Calculating at least one acceleration value along the measurement direction and / or within the measurement direction corridor has the advantage of being able to evaluate the acceleration pattern characteristics of an accident occurring in a specific direction. This means that false triggers due to, for example, careless handling of the child restraint can be avoided. This includes ruptures when installing the child restraint and / or when repositioning the child restraint in the vehicle. A child or infant may also trigger acceleration forces on or in the child restraint, which may also result in false triggers. By taking into account specific acceleration values, preferably occurring along specific directions, undesired triggers can be prevented. Furthermore, evaluation of calculated acceleration values ​​occurring along (different) predefined axes can be used to implement accident-specific triggering behaviors. For example, different gas bags and / or gas bag compartments, or the same gas bag and / or gas bag compartments in a different sequence, can be filled in a frontal accident rather than a side collision. As already explained, the occurrence of a specific acceleration value does not necessarily directly result in the triggering of the respective protective measure, but can be a prerequisite for a specific trigger.

[0023] In one embodiment, multiple acceleration values, particularly multiple first acceleration values, are determined over time. The determined or calculated first acceleration values ​​can be taken into account when triggering active protection measures. In one embodiment, these acceleration values ​​are evaluated over time and compared with a characteristic value progression over time, so that triggering occurs only if there is at least a substantial match. However, various other evaluations can also be performed over time according to the present invention. For example, threshold comparisons can be performed at specific points in time.

[0024] In one embodiment, the warning mode is employed when at least one warning criterion is met. The warning criterion may be, for example, when one of the acceleration values, in particular one of the calculated acceleration values, e.g., the first calculated acceleration value, exceeds a threshold value (at least once). The threshold value is preferably 0.5 g (g = normal acceleration due to gravity = 9.81 m / s 2 ) and / or less than 5 g. The thresholds are particularly preferably in the range of 1.5 g to 2.5 g. As a result of these thresholds, the warning mode is only activated at higher acceleration values ​​in a predefined direction. At the same time, the thresholds are not set so high that a possible trigger situation is "overlooked" or recognized too late.

[0025] An advantage of the present invention is that at least the acceleration value-based warning criteria can be determined using a simple force sensor, which is very energy-efficient in use, so that only a small energy storage is required to implement the described method within the device.

[0026] Furthermore, preferably additional warning criteria can also be defined. For example, the additional warning criterion may be that the measured temperature is within a predetermined interval, preferably between -30°C and 100°C, for example between -20°C and 40°C. In one embodiment, the temperature is measured on the active protection means (e.g., airbag) itself and / or on the control unit.

[0027] The warning mode can be considered a preliminary step to triggering. In the warning mode, for example, it is possible to check whether active protection measures (in particular whether an airbag) should be triggered at very short intervals, for example at least every 2 milliseconds (ms), preferably every millisecond. Possible check intervals can be in the range of 0.2 ms to 0.8 ms.

[0028] In other words, in the warning mode, at least one trigger criterion can be repeatedly checked. This can be, for example, monitoring of at least one acceleration value determined based on at least one of the acceleration sensor signals and / or a value calculated based on this first acceleration value. In one embodiment, a differential velocity calculated based on the at least one acceleration value is monitored, or exceeding a threshold value by the calculated differential velocity is used as the trigger criterion.

[0029] In one embodiment, the differential velocity is calculated using several acceleration values, for example, one acceleration value (e.g., for a different sensor axis) can be determined for each received acceleration sensor signal.

[0030] According to the present invention, the same force sensor can be used as the acceleration sensor to determine at least one trigger criterion and at least one warning criterion. Therefore, the hardware requirements for implementing the method are low. The fewer sensors required, the lower the power consumption.

[0031] The present invention contemplates calculating several differential velocities for at least one acceleration value and comparing these to several different thresholds. For example, thresholds that change over time can be used. In one embodiment, the differential velocities are calculated multiple times, starting from the state when the transition to warning mode last occurred.

[0032] In one embodiment, acceleration values ​​(of one or several axes) are integrated over time or added in another suitable manner to determine the differential velocity (compared to the velocity at the transition to the warning state) starting from that point in time. Any acceleration value can be taken into account for this purpose.

[0033] In one embodiment, a trigger is associated with at least two trigger criteria: a) The differential velocity exceeds a threshold value that is assigned to a time point, possibly individually. b) The acceleration values ​​used to determine the differential velocity are (primarily) within the target corridor with respect to their direction of action.

[0034] The target corridor can be specified by a vector. Preferably, the target corridor is specified by a vector and an angle. The target corridor can be the measurement direction corridor already described. The target corridor can be a one-dimensional vector, a two-dimensional surface, or a three-dimensional body. In this context, the term target corridor includes the term target direction, which is preferably a cone.

[0035] Determining a valid direction can include summing and possibly normalizing acceleration vectors determined or measured since the (last) transition to trigger mode, which can ensure that the differential velocity that ultimately results in a trigger is based primarily on accelerations / acceleration vectors that are within the target corridor (e.g., more than 50%).

[0036] In one embodiment, the trigger criterion can be met if the calculated differential velocity still has a sufficiently high value after a predefined dead time, which can be selected, for example, within an interval of 1 to 50 ms, preferably 2 to 10 ms.

[0037] After this dead time is exceeded, the differential rate can be compared to a threshold that, in one embodiment, decreases (continuously) within the time interval following the dead time, so that if a correspondingly high differential rate is present during this period, triggering becomes more likely. After this time interval, in at least one embodiment, the threshold increases again within a subsequent time interval. Preferably, there is a maximum time that guarantees exiting the warning mode again, provided the trigger criteria were not met within the previous time period.

[0038] The warning mode may be terminated if one or more cancellation criteria are met. The cancellation criteria may include: i) time-out, in particular exceeding the maximum time interval since the (last) transition to warning mode, and / or ii) exceeding the maximum number of calculation steps, in particular calculation step c), and / or iii) the acceleration value, in particular the first acceleration value, falls below a threshold value; and / or iv) The differential velocity calculated based on one / more acceleration values ​​is below a threshold value.

[0039] The triggering of active protection measures can also be linked to several trigger criteria, which, in addition to at least one of those already mentioned, can be chosen from the following: - The measured temperature is within a specified interval, preferably between -30°C and 100°C, for example between -20°C and 40°C. In one embodiment, the temperature is measured on the active protection means (e.g. airbag) itself and / or on the control unit. - the further, in particular secondary, acceleration sensor unit determines or calculates an acceleration value that exceeds a threshold value in at least one measurement since the start of the warning mode. For example, this may be a threshold value of 2.5 g. In one embodiment, this may be an acceleration value greater than 2 g. - The secondary acceleration sensor unit calculates and / or measures acceleration values ​​that, on average (using an appropriate average value) since the start of the warning mode, exceed a predefined threshold, which may be 2g or 1.5g.

[0040] In one embodiment, the method includes at least one calibration step. Preferably, the method can implement a calibration state, i.e., a mode in which calibration is performed over a certain period of time. In the calibration mode or step, a reference plane is determined using a gravity vector, in particular gravity g. This reference plane can be used to determine a measurement direction or a measurement direction corridor. The gravity vector can be determined using an acceleration sensor signal.

[0041] In one embodiment, the reference plane may be the vehicle plane, preferably including the direction of the driving vector, and the vehicle plane is determined using restraint reference data, for example, restraint tilt angle.

[0042] The transition to calibration mode can be made from lock mode. After calibration mode, it is possible to transition to standby mode. In one embodiment, calibration mode is also standby mode or a possible embodiment thereof. A switch from calibration mode or standby mode back to lock mode can be envisaged when a predetermined condition is not met (or is no longer met), for example immediately or if this is the case for a predetermined time (e.g., 2 minutes).

[0043] In the calibration mode, a calibration loop can be (several times) passed through. For this purpose, in a first step, the acceleration can be detected by the acceleration sensor unit. By detecting the orientation related to the acceleration due to gravity, the seat orientation or the seat coordinate system or the coordinate system of the acceleration sensor unit can be determined in a second step. Then, in a third step, the acceleration in the measurement direction (e.g. in the direction of travel of the vehicle and / or in the direction of the horizontal component of the direction of travel) can be determined.

[0044] Here, "in the direction of the horizontal component of the running direction" means in particular that the direction is oriented horizontally (i.e. perpendicular to the acceleration due to gravity) and that there is no lateral component related to the running direction. Finally, it can be envisaged to repeat the above steps at a predetermined frequency until a cancellation event occurs.

[0045] Therefore, specifically, the calibration loop can include the following steps, whereby in this embodiment it is assumed that the x-axis of the acceleration sensor unit has no lateral component, and that the coordinate system of the vehicle seat coincides with the coordinate system of the vehicle and the x-axis of the acceleration sensor unit, or that the corresponding coordinate systems are raised by an angle α. In other words, the x-axis of the acceleration sensor unit intersects with the vehicle plane at an acute angle α. Furthermore, for this embodiment it is assumed that the z-axis of the acceleration sensor unit also has no lateral component and is perpendicular to the x-axis. 1. Measurement of accelerations a1 and a3 in the direction of each axis. 2. Determining the angle β relating the vehicle plane to the horizontal plane. This may be intended to only consider realistic angles of β, for example, so that the amount of β in degrees can be up to 25. 3. Acceleration a in the direction of travel (in the plane of the vehicle) by adding the corresponding components of a1 and a3 dr and / or a in the direction of the horizontal component of the strike direction drh decision.

[0046] In addition to the inclination of the vehicle plane relative to the horizontal plane, further offset angles according to the invention can be taken into account. - offset angle γ: inclination of the child seat coordinate system relative to the vehicle plane, - Offset angle α: Inclination of the coordinate system of the acceleration sensor unit relative to the child seat coordinate system.

[0047] γ can be estimated and / or determined by a separate measurement (e.g., if the vehicle is known to be currently on a level surface) and / or can be specified by input from a user. In one embodiment, γ is estimated using a value preferably between 0 and 30°, and more preferably between 10 and 20°.

[0048] The method may include storing values ​​and / or reading stored values. If no measurements are available or there are too few measurements, a preset value of β can be used at the start of the calibration loop. Alternatively, a value of β determined during a previous use of the child seat (in particular the last value determined, which may be stored for this purpose) can be used.

[0049] In one embodiment, it may be envisaged that transition from calibration mode to warning mode is not permitted until a predetermined number of measurements have been taken.

[0050] In one embodiment, it may be assumed that calibration is stopped upon entering warning mode.

[0051] In another embodiment, it may be envisaged that the calibration continues to run in the background, in which case the calculations may (preferably) still be based on the calibration measurement directions (or corresponding measurement direction corridors) determined when entering the warning mode, or the calculations may be based on continuously updated measurement directions (or corresponding measurement direction corridors).

[0052] [First Variation: Averaging] In one embodiment, it may be provided to form an ensemble of measurements (in calibration mode) such that the ensemble includes multiple measurements. Preferably, the multiple measurements of the ensemble may consist (solely or partially) of directly consecutive measurements. The multiple and / or number of directly consecutive measurements may be greater than 100, or greater than 1000, or greater than 10000. The multiple and / or said number of directly consecutive measurements may include measurements from a time interval of greater than 1 second, or greater than 5 seconds, or greater than 20 seconds, and / or measurements from a time interval of up to 10 minutes or up to 90 seconds.

[0053] Furthermore, it may be envisaged to form successive ensembles that immediately follow one another or that overlap (in each case with respect to the measurements associated with the ensemble). In particular, it may also be envisaged to form only a single ensemble and to continuously update the ensemble by adding a new (preferably current) measurement to the ensemble and instead removing another (preferably oldest) measurement from the ensemble.

[0054] Once the ensemble is formed, in connection with the second step, it may be envisaged to first calculate each of a1 and a3 from the individual measurements using an appropriate average value (e.g., arithmetic mean, geometric mean, harmonic mean or median), and then infer the angle β or the angle sum α+β from this average value. It may also be envisaged to determine β or α+β from the results thus obtained by calculating the angle or angle sum for each individual measurement and forming an appropriate average value.

[0055] [Second Variation: Iterative Adjustment] As an alternative to averaging (first variant), it may be envisaged to iteratively update the angle β in the calibration mode. To do this, β itself can be iteratively updated, or each of a1 and a3 is iteratively updated and used to calculate β.

[0056] If β itself is iteratively updated, it may be assumed that it is necessary to offset the known value of β (in particular, the value of β that has been determined by measurement, preferably the most recent value of β that has been determined by measurement) with respect to the value determined from the new measurement. alt and the value determined from the new measurement is β neu For example, β=a*β alt +b*β neu can be applied, where a and b are coefficients. Preferably, a and b are each constants, preferably a+b=1, and a is preferably greater than b, in particular at least twice as large. As soon as new measurement results are available, β alt can be set to the value of β and a new offset can be implemented. In this way, a current value of β that is robust to outliers can always be provided with very little memory and low energy consumption.

[0057] In one embodiment, at least one calculated acceleration value can also be determined or updated iteratively, as described above for β, i.e., by offsetting a known value each time by a value determined from a new measurement. Preferably, the calculation is also performed using a factor (possibly a constant) as described above for β.

[0058] In one embodiment, at least one sleep mode criterion is determined, in particular using the acceleration value and / or the sensor signal, so that if the at least one sleep mode criterion is present, the sleep mode is adopted. This sleep mode or sleep mode criterion can be used to reduce the energy consumption of the device implementing the method. For example, in the sleep mode, the acceleration value, in particular the first acceleration value, can be determined at a first frequency that is (significantly) lower than a second frequency associated with the non-sleep mode.

[0059] The sleep mode criterion may be a comparison of the sensor signal or acceleration value to an expected acceleration value that occurs when only acceleration due to gravity occurs. In this regard, a particular tolerance may be provided such that some or all of the acceleration sensor measurements must lie around the value of acceleration due to gravity over a predetermined time interval to meet the sleep mode criterion.

[0060] The sleep mode may be exited when at least one of the determined acceleration values ​​or measured acceleration sensor signals is no longer within a specified interval. For example, after exiting the sleep mode, the previously described calibration mode or calibration step may be performed.

[0061] If the harness state is not already a criterion for leaving the locked mode, the harness state can alternatively or additionally, preferably independently of the aforementioned criteria, be taken into account as a criterion for entering the sleep mode. It can be assumed that the sleep mode is entered (immediately or after a predetermined time) when the harness is opened. The sleep mode can be left again when the harness is closed.

[0062] The object stated at the beginning is also solved by the following method, which provides the same or similar advantages as those described.

[0063] A method for triggering (active) protection measures, comprising: a) receiving an acceleration sensor signal from at least one acceleration sensor; b) calculating at least one first acceleration value; c) calculating the differential velocity; d) determining a trigger signal based on at least the differential velocity; e) triggering the airbag based on the trigger signal; A method comprising:

[0064] The differential velocity can be based on the first acceleration value or directly on the acceleration sensor signal, in which case the calculation of at least one first acceleration value may be omitted, if desired.

[0065] A method for triggering (active) protection measures, comprising: a) receiving a first acceleration sensor signal from at least one acceleration sensor; b) determining, preferably iteratively, at least one measurement direction and / or measurement direction corridor based on the first acceleration sensor signal; c) receiving a second acceleration sensor signal from the at least one acceleration sensor (described above); d) determining a trigger signal based on at least the second acceleration sensor signal; e) triggering the airbag based on the trigger signal; A method comprising:

[0066] The first acceleration sensor signal and the second acceleration sensor signal may be signals derived from different acceleration sensors. Alternatively or additionally, they may be signals received at different times, with at least one second acceleration sensor signal being received in each case after the first acceleration sensor signal. In one embodiment, the second acceleration sensor signal is derived from the same acceleration sensor as the first acceleration sensor signal.

[0067] A method for triggering (active) protection measures, comprising: a) determining at least one measurement direction and / or measurement direction corridor; b) receiving an acceleration sensor signal from at least one acceleration sensor; c) calculating at least one first acceleration value; d) comparing the at least one first acceleration value with a measurement direction and / or a measurement direction corridor; e) determining a trigger signal based at least on the comparison result; f) triggering the airbag based on the trigger signal; A method comprising:

[0068] A method for triggering (active) protection measures, comprising: a) checking a condition for entering a standby mode, the condition being: - correct attachment of the child restraint system to the vehicle seat, - Detection of children in car seats, - correct fixation of the child in the restraint system; - Correct placement of the restraint support feet a checking step including at least one of the following conditions: b) receiving an acceleration sensor signal from at least one acceleration sensor; c) determining a trigger signal based on at least one acceleration value and / or acceleration sensor signal; d) triggering the airbag based on the trigger signal; A method comprising:

[0069] The protection means of the aforementioned method may be an airbag. The method may be used in particular with a child restraint system as described below. The method may in each case be combined with the above-mentioned embodiments, in particular with the embodiments and / or partial aspects thereof of claims 1 to 11. The method is suitable for triggering protection means in a vehicle.

[0070] The object stated at the outset is also solved by a computer-readable storage medium or computer-readable memory having instructions for carrying out one of the methods already described.

[0071] Furthermore, the object can be solved by a control and regulation unit that is designed to implement the above method during operation.

[0072] Advantages similar to those already described in connection with the method are provided.

[0073] The object stated at the outset is also solved by a child restraint device, in particular a child car seat and / or an impact shield, for installation in a vehicle or by components of such a vehicle, having a longitudinal axis, a transverse axis and a vertical axis, wherein the child restraint device can comprise: at least one (active) protection means, in particular an airbag with at least one inflatable gas bag; - at least one drive unit for activating at least one protective means, in particular a gas generator; - at least one control unit for activating the drive unit by a trigger signal; at least one sensor unit having a first acceleration sensor and a third acceleration sensor for outputting a first acceleration sensor signal and a third acceleration sensor signal, respectively;

[0074] The control unit preferably receives the acceleration sensor signals and determines whether the drive unit is activated based on the first acceleration sensor signal and the third acceleration sensor signal.

[0075] Here too, the same advantages as those already explained in connection with the method are provided. As explained, the child restraint device can be equipped with a sensor unit having at least two acceleration sensors. Preferably, several of these acceleration sensors are used so that only accelerations occurring in a specific direction are utilized. Alternatively, several acceleration values ​​acting in different directions can be taken into account, but separate evaluations should be performed according to the invention.

[0076] The child restraint device or component may include a primary sensor unit and a secondary sensor unit, each having at least two acceleration sensors. In one embodiment, three acceleration sensors are provided, preferably providing acceleration sensor signals orthogonal to one another. In one embodiment, the acceleration sensors of the primary sensor unit are sampled more frequently than those of the secondary sensor unit. The primary sensor acceleration unit may be sampled at a first predetermined frequency, for example, greater than 10 Hz, preferably greater than 100 Hz, or even greater than 1 kHz. In one embodiment, the acceleration sensors of the primary sensor unit are sampled at a sampling rate less than 10 kHz.

[0077] In one embodiment, a first acceleration sensor (x-axis) and a third acceleration sensor (z-axis) for detecting a first acceleration value (x-axis) and a third acceleration value (z-axis), respectively, are arranged in a detection direction that extends in or parallel to a plane spanned by the vertical axis and the longitudinal axis of the child restraint device.

[0078] In one embodiment, the first and third acceleration sensors are arranged (at least substantially) orthogonal to each other. When the term "substantially" is used in connection with directional information, this can mean (here, above, and / or below) that the directional information deviates from the specified direction by up to 20° or up to 15°. The sign of the deviation is irrelevant here, and thus spans the interval between +20° and -20° or +15° and -15°.

[0079] The second acceleration sensor (y-axis) is aligned (at least substantially) parallel or coaxial with the lateral axis of the child restraint.

[0080] To detect the first acceleration value, the acceleration sensor may be arranged in one / said detection direction having an angle of more than 5° and / or less than 30° relative to the longitudinal axis of the vehicle.

[0081] The possibilities discussed so far for aligning the acceleration sensors are advantageous, in particular with regard to any calculations and decisions (e.g., by a control unit) made based on the measured accelerations. However, other configurations are possible. In principle, aligning different acceleration sensors orthogonally to one another is not necessary. By aligning them at different angles to one another, the accuracy of the measurement in one direction can be improved at the expense of the accuracy of the measurement in another direction.

[0082] For example, it is also possible to position two or three acceleration sensors (preferably symmetrical with respect to the longitudinal axis of the child car seat or the longitudinal axis of the vehicle) so that each of these acceleration sensors has a component (preferably of the same size) in the direction of the longitudinal axis of the child car seat or the longitudinal axis of the vehicle. This has the advantage that the detection of the largest expected acceleration (i.e. in the direction of travel of the vehicle when traveling straight or in the direction of the longitudinal axis of the vehicle) can be distributed over all three acceleration sensors and can therefore be particularly efficient, and therefore higher accelerations can be detected with the same measurement range of the individual acceleration sensors. In one embodiment, for example, the two or three acceleration sensors can be arranged at 45° to the longitudinal axis of the vehicle or the longitudinal axis of the child car seat and at the same time be perpendicular to each other.

[0083] In principle, most aspects of the invention can also be realized with a single sensor, which preferably lies in the plane spanned by the x- and z-axes and can be tilted upward at an angle of 20° to 40° relative to the x-axis.

[0084] The child restraint according to the invention may have at least one acceleration sensor unit with acceleration sensors for two or more directions (e.g., a three-axis sensor). The acceleration sensor unit may be provided near the rear side of the child car seat (i.e., on the side of the child car seat facing the backrest of the vehicle seat). Additionally or alternatively, the acceleration sensor unit may be provided near the underside of the child car seat (i.e., on the side of the child restraint facing the seat bottom of the vehicle seat). Preferably, the acceleration sensor unit is arranged in the center (in relation to the lateral direction of the child restraint) and / or close to the (imaginary) connection line between the rear fastening means of the child restraint. Here, close may mean a distance of up to 10 cm.

[0085] The first acceleration sensor (x-axis) can be aligned so that its lateral component is zero. In particular, the first acceleration sensor can be aligned at least substantially (with respect to the direction of travel when driving straight ahead) so that it rises slightly from rear to front (see offset angle γ).

[0086] Preferably, γ is an acute angle, more preferably an angle greater than 5° and / or less than 30°, and particularly preferably an angle of 7° to 18°.

[0087] The second acceleration sensor (y-axis) of the acceleration sensor unit can be aligned laterally perpendicular to the first acceleration sensor.

[0088] The third acceleration sensor (z-axis) can be aligned perpendicular to the first and second acceleration sensors, respectively.

[0089] Several acceleration sensor units may be installed within the child restraint system, with at least one of the acceleration sensor units acting as a primary unit.

[0090] The (primary) acceleration sensor unit can detect acceleration or measure acceleration values ​​at a first predetermined frequency. The predetermined frequency can be, for example, greater than 10 Hz, preferably greater than 100 Hz, particularly preferably greater than 1 kHz. In addition, the predetermined frequency may possibly be up to 10 kHz.

[0091] The secondary acceleration sensor unit can detect acceleration or measure acceleration values ​​at a second predetermined frequency, which is preferably lower than the first predetermined frequency (e.g., 30% to 70% of the first predetermined frequency).

[0092] The child restraint may have at least one energy storage device, in particular a battery (e.g., a lithium-ion accumulator), for supplying the control unit and / or the gas generator. In one embodiment, the gas generator is powered by a fluid reservoir and / or pyrotechnics. However, it is also possible for the gas generator to be electrically operated. Preferably, the control unit in the child restraint is powered by its own energy storage unit, eliminating the need to connect the child restraint to the vehicle's electrical system.

[0093] Further advantageous embodiments are set forth in the dependent claims.

[0094] The invention will now be described with reference to several drawings. [Brief explanation of the drawings]

[0095] [Figure 1] FIG. 1 is a perspective view of a first child car seat (without base) having an airbag. [Figure 2] 2 is a bottom view of the child car seat according to FIG. 1. FIG. [Figure 3] FIG. 10 is a side view of another child car seat with an airbag deployed or inflated. [Figure 4] FIG. 1 is a (highly) schematic representation of measured acceleration values ​​in a vehicle on flat ground. [Figure 5] FIG. 2 is a (highly) schematic representation of measured acceleration values ​​in a vehicle traveling uphill. [Figure 6] FIG. 10 is a further illustration of calculated acceleration values ​​within a vehicle. [Figure 7] 4A and 4B are schematic diagrams of several operating modes of a control unit for triggering the airbag of the child car seat according to FIGS. 1 and 3; [Figure 8a] FIG. 1 is a schematic diagram of a measurement direction corridor. [Figure 8b] FIG. 1 is a schematic diagram of a measurement direction corridor. [Figure 9] FIG. 1 is one of several different diagrams illustrating criteria for controlling an airbag. [Figure 10] FIG. 1 is one of several different diagrams illustrating criteria for controlling an airbag. [Figure 11] FIG. 1 is one of several different diagrams illustrating criteria for controlling an airbag. [Figure 12] FIG. 1 is one of several different diagrams illustrating criteria for controlling an airbag. [Figure 13] FIG. 1 is one of several different diagrams illustrating criteria for controlling an airbag. [Figure 14] FIG. 1 is one of several different diagrams illustrating criteria for controlling an airbag. [Figure 15] FIG. 1 is one of several different diagrams illustrating criteria for controlling an airbag. [Figure 16] FIG. 1 is one of several different diagrams illustrating criteria for controlling an airbag. [Figure 17] FIG. 1 is one of several different diagrams illustrating criteria for controlling an airbag. [Figure 18] FIG. 1 is one of several different diagrams illustrating criteria for controlling an airbag. [Figure 19]1 is a schematic diagram of a control unit in communication with a sensor unit and a gas generator for inflating an airbag; [Figure 20] FIG. 1 is a diagram of different evaluation strategies for acceleration values ​​measured on different axes. [Figure 21] FIG. 1 is a diagram of different evaluation strategies for acceleration values ​​measured on different axes. [Figure 22] FIG. 1 is a diagram of different evaluation strategies for acceleration values ​​measured on different axes. DETAILED DESCRIPTION OF THE INVENTION

[0096] In the following description, identical and identically acting parts are designated by the same reference numerals.

[0097] 1 shows a child car seat 10 having a main body 20, an impact shield 50 and an airbag 70 (not shown in detail). The main body 20 comprises a seat section 21 (having a central section 21M, a left side 21L and a right side 21R), a backrest 22, side wings (or side bolsters) 23, a headrest 24, side impact protection 29 and fastening means 28. The impact shield extends at least substantially laterally and has a central section 51, a left section 52 and a right section 53 and a cover 57. A first gap 121 is formed between the central section 51 (in particular its bottom surface 51B, which is not visible in the drawings) and the central section 21 of the seat section.

[0098] 2 shows the child car seat 10 according to FIG. 1 in a view from below, provided with an airbag 70 having a gas bag 71 (located in the front compartment of the bottom surface 21B of the seat compartment 21), a gas generator 72 and a sensor unit 74. The sensor unit 74 is communicatively connected to a control unit (or controller) 100, which is not shown in FIG. 2.

[0099] Figure 3 shows a child car seat 10 which may generally correspond to the child car seat according to Figures 1 and 2, the differences being explained below. The child car seat 10 according to Figure 3 comprises a body 20 having a base 90 (in contrast to that according to Figure 1), an impact shield 50 and an airbag 70. As with the child car seat 10 of Figure 1, the body 20 comprises a seat section 21, a backrest 22 and a headrest 24. The impact shield 50 extends (at least substantially) in the transverse direction. The airbag 70 comprises a gas bag 71 which, in a non-inflated state (not shown), is arranged around a central section of the impact shield 50 (not shown) and a gas generator 72 which is preferably arranged in a cavity of the impact shield 50 and is communicatively connected to a control unit (controller) 100.

[0100] The base 90 has support feet 92, fastening means 28 (in particular Isofix anchors), and a control unit 100 (not shown), which is communicatively connected, for example via a bus, to a sensor unit 74 located in, on or near (for example at a distance of less than 10 cm or less than 5 cm) the fastening means 28.

[0101] 3 shows the airbag 70 in its inflated state, as described. The gas bag 71 is filled with gas so that the first gap 121 and the second gap 122 are (now) narrower to (initially) restrain the child from moving forward relative to the child seat 10. A ridge in the upper surface is configured to receive the child's head. The gas bag 71 in this embodiment may have a volume of at least 3 liters, preferably at least 5 liters, and / or a volume of less than 15 liters, preferably less than 10 liters.

[0102] FIG. 19 schematically illustrates the gas generator 72 and the sensor unit 74 communicatively connected to the control unit 100. In one embodiment of the invention, the sensor unit 74 is a three-axis sensor capable of determining acceleration values ​​rawX, rawY, and rawZ on three different axes (x, y, and z) by means of mutually orthogonal acceleration sensors 74x, 74z, and 74z. Corresponding sensor signals are communicated to the control unit 100, for example, via a bus. The control unit 100 receives the sensor signals via an interface 106. The interface 106 is also communicatively connected to the gas generator 72. Here, bus communication can also be established. The communication connection to the gas generator 72 is used to check the status of the gas generator 72 and / or to activate the gas generator 72 via a trigger signal to fill the gas bag 71.

[0103] The control unit 100 can be a control and coordination unit. It can be either a (mini) computer customized for a specific application or dedicated hardware. The control unit 100 shown in Figure 19 comprises a memory 102 for storing status data and for storing instructions executed by a computing unit 104 to implement an appropriate control strategy.

[0104] The corresponding control strategy is shown in Figure 7. In one example embodiment, the control unit 100 may implement a state machine having operating states substantially as shown in Figure 7. These are a locked mode 200, a standby mode 210, and an ignition mode 220.

[0105] It may be assumed that the control unit 100 switches to standby mode 210 (and otherwise remains in lock mode 200) only when one or more (possibly all) of the following operating conditions are met: - The child seat 10 is correctly connected to the vehicle seat (preferably correctly connected Isofix or LATCH). - a child is present in the child seat 10 (detected in particular, for example by a weight sensor in the seat compartment). - The child is properly immobilized, for example: - the harness is closed (all, preferably both, belt tongues of the shoulder and lap belts are correctly connected to the crotch belt harness), and, if necessary, additionally or alternatively, one or more belts are tensioned above a predefined threshold. - the impact shield 50 is correctly installed (all fastening means are correctly installed, the respective engagement means are engaged with each other, and if necessary, additionally or alternatively, one or more belts are tensioned above a predefined threshold). - the support foot 25 is correctly attached, in particular loaded (the support foot 25 is resting with its lower end resting on the vehicle floor, while its preferably rotatable (in particular foldable for space-saving storage) upper end is connected to other components of the child seat 10, in particular the seat base and / or seat compartment 21 and / or backrest 22).

[0106] The transition between the lock mode 200 and the standby mode 210 can be achieved by a switch that opens or closes depending on the result of a measurement of an associated sensor, for example, thereby closing an electrical circuit (e.g., by an energy source).

[0107] In standby mode 210, the child seat 10 is essentially in a state in which it is possible to trigger the airbag 70. In other words, all the general conditions are met such that reliable measurements can be taken to ensure that the specific triggering criteria that ultimately lead to ignition are in fact met.

[0108] In one example embodiment, the standby mode 210 includes three states: a calibration mode 211, a warning mode 213, and a sleep mode 215. After exiting the lock mode 200, the state machine implemented by the control unit 100 preferably enters the calibration mode 211, which in one example embodiment goes through a calibration loop. In this calibration loop, acceleration values ​​rawX, rawY, and rawZ are measured and, based on these, an attempt is made to determine the cardinal orientation of the acceleration sensors 74x, 74y, and 74z relative to the acceleration due to gravity. Depending on the available information, the vehicle's direction of travel or movement in a horizontal plane drh (perpendicular to gravity) or in a vehicle plane dr (e.g., lying through the vehicle's axles) can be determined based on the acceleration values ​​rawX, rawY, and rawZ.

[0109] This driving direction can be used to check the criteria for entering the warning mode and the trigger criteria. When the airbag 70 is in the standby mode 210 but the only acceleration measured over a given time period is the acceleration due to gravity, g, a sleep mode 215 is provided to conserve energy. This means that it can be assumed that the vehicle is not moving, or is moving only to such a small extent that it is not meaningful to trigger the airbag 70. The system's transition to sleep mode 215 can be based on a comparison of the acceleration values ​​rawX, rawY, and rawZ with predicted values ​​based on the acceleration due to gravity. A certain tolerance can be provided here. If the criteria for sleep mode are no longer met, the system returns to calibration mode 211.

[0110] In one embodiment, a calibration loop is continuously executed in the calibration mode 211 to detect and take into account repositioning of the vehicle at all times. In other words, the vehicle plane is continuously re-determined by the measured gravitational acceleration g to estimate or calculate the positioning of the child car seat 10 and / or the sensor unit 74 based on the vehicle plane.

[0111] A transition to warning mode 213 can then occur if the calculated x acceleration value aX (in the vehicle plane, corresponding to adr in this example embodiment) exceeds a predefined threshold. This threshold can be, for example, 2×g (i.e., twice the acceleration due to gravity). The basic idea is therefore that control unit 100 transitions to warning mode 213 when a significant acceleration in the measurement direction (which in the example embodiment described corresponds to the direction of travel) is detected, such as would be usual in the case of an accident but not normally achieved during braking. However, to avoid false triggers, the example embodiment according to FIG. 7 does not directly switch to ignition mode 220. Instead, the example embodiment provides at least one trigger criterion that is checked in warning mode 213 before the actual trigger occurs.

[0112] An independent or additional aspect of the present invention is that the trigger criteria separately consider accelerations on multiple different axes. In a preferred embodiment, illustrated in more detail below, only acceleration forces occurring substantially in the vehicle's direction of travel are taken into account. Figures 8a and 8b show the corresponding measurement direction or measurement direction corridor 3. In the embodiment described below, only acceleration values ​​occurring along the vehicle's longitudinal axis xF may be taken into account, regardless of the orientation of the acceleration sensors 74x, 74y, and 74z. However, as shown in Figures 8a and 8b, it is also possible to allow a corridor 3 of acceleration values ​​to be taken into account when determining the trigger criteria. As shown in Figures 8a and 8b, the corridor 3 may be a cone whose origin is at the center of the child car seat 10 or the sensor unit 74. It will be appreciated that such a cone may be reduced to a range of angles when only two acceleration sensors, e.g., 74x and 74z, are used.

[0113] In one example embodiment, the sensor unit 74 may be precisely mounted so that the y acceleration sensor 74y is precisely oriented parallel or coaxially with the vehicle's lateral axis yF (e.g., parallel to the vehicle's axis). Since child seats 10 are typically mounted with at least substantially the same lateral orientation (the child's gaze is aligned with or opposite the direction of travel), the y acceleration sensor 74y can be mounted in the child seat 10 ex-factory in a corresponding manner. Because the x acceleration sensor 74 and the z acceleration sensor 74z are positioned orthogonal to each other and to the y acceleration sensor 74y, no (lateral) acceleration forces act on the x acceleration sensor 74x and the z acceleration sensor 74z when the vehicle is traveling in a straight line. This means that a two-dimensional view such as that shown in FIGS. 4 to 6 can be obtained. The y component of the acceleration can be ignored (at least initially) in this example embodiment.

[0114] When the vehicle is traveling parallel to the horizontal plane on a flat road or is stationary, as shown in FIG. 4, the x acceleration sensor 74x may be tilted by an angle α with respect to the horizontal plane. This may be due to the fact that the x acceleration sensor 74x is tilted with respect to the flat arrangement of the child car seat 10 (with respect to the vehicle plane). In the example embodiment shown in FIG. 4, the coordinate system of the child car seat 10 is identified with the coordinate system of the vehicle to account for the angle α. Thus, in this illustration, the longitudinal axis xS, lateral axis yS, and vertical axis zS of the child car seat coincide with the longitudinal axis xF, lateral axis yF, and vertical axis zF of the vehicle. Despite the vehicle being horizontal, the acceleration g due to gravity is resolved into a measured x acceleration value rawX and a measured z acceleration value rawZ, which are detected by the sensor unit 74 tilted by the angle α.

[0115] In Figure 5, the vehicle is now traveling uphill relative to the horizontal plane or is positioned accordingly. As shown in Figure 5, the road, and therefore the vehicle plane, is tilted by an angle β relative to the horizontal plane. The coordinate system of the sensor unit 74 is therefore tilted (in this example, about the vehicle's lateral axis yF) relative to the horizontal plane by the sum of angles α and β. The acceleration g due to gravity is much more distributed (the x acceleration value increases) across the x acceleration sensor 74x and the z acceleration sensor 74z. If the angle α is known and the child car seat 10 is assumed to be positioned parallel to the plane of the vehicle, then the acceleration a in the direction of travel can be calculated as dr can be easily determined from the measured acceleration values ​​rawX, rawZ after appropriate calibration (see calibration mode 211). The angle α can be set, for example, based on an external input or ex-factory. If the angle α is not known, in one example embodiment, the horizontal component of the travel direction, i.e., the acceleration a in the direction of the horizontal plane, drh can be determined (see Figure 20). Both approaches are sufficient to achieve a (significant) improvement in trigger behavior compared to the state of the art.

[0116] FIG. 6 introduces an additional angle, the γ angle, which indicates the inclination of the child car seat 10 relative to the vehicle plane about the lateral axis yF. This angle γ models the fact that vehicle seats are often tilted with respect to the vehicle plane, resulting in the child car seat 10 being positioned at an angle. In one example embodiment, the angle γ is estimated. In another example embodiment, a separate measurement of the angle γ can be made (e.g., if it is known that the vehicle is currently on a horizontal plane), or the angle γ can be set by user input. If γ is estimated, a value between 0 and 30° is preferably used, more preferably between 10 and 20°. If the angle γ is unknown, in one example embodiment, the horizontal component of the direction of travel, i.e., the acceleration a in the direction of the horizontal plane, is used. drh can be determined (see Figure 20). This approach is sufficient to achieve a (significant) improvement in trigger behavior compared to the state of the art.

[0117] As already explained, the acceleration in the direction of travel a dr (or, according to the embodiment as described, instead a drh ) can be used to determine whether the child car seat 10 should switch from the calibration mode 211 to the warning mode 213. Thus, the acceleration a dr (In some cases, a drh ) can be used to determine whether ignition of the airbag 70 is indicated, i.e., whether a transition from warning mode 213 to ignition mode 220 is indicated. In this regard, several different strategies exist. In particular, criteria can be provided to determine whether to maintain warning mode 213, whether to indicate a change to ignition mode 220, or whether to cancel warning mode 213 (no ignition) (e.g., return to calibration mode 211).

[0118] In one example embodiment, the value a dr (In some cases, a drh ), which is continuously compared over time with two curves. The first curve specifies thresholds over time that cause the system to return to calibration mode 211. The second curve also specifies thresholds over time that, if exceeded, cause a switch from warning mode 213 to ignition mode 220.

[0119] A specific acceleration value a dr (or a drh ), in one example embodiment, a differential velocity Δv or Deltav is calculated and taken into account from the time the control unit transitions to warning mode 213. The differential velocity Deltav is preferably based on full acceleration information (not just acceleration in the measured direction). For example, the measured acceleration values ​​rawx, rawy, rawz can be used to determine the differential velocity in three-dimensional space (since transitioning to warning mode).

[0120] In one example embodiment, the direction of the acceleration vectors used to determine the differential velocity can be used as an additional trigger criterion (directional criterion). Thus, after the differential velocity exceeds a threshold (see the discussion of Figures 13-15), it can be checked whether the sum of the acceleration vectors is within a target corridor. The target corridor can be measurement direction corridor 3 shown in Figures 8a and 8b.

[0121] FIG. 9 shows a first curve, which is substantially static over time, and for cancellation, a certain threshold is set from t1 to t max The curves are to be understood such that the measurements indicated by diamonds by way of example do not result in cancellation and result in the maintenance of the warning mode 213. As an additional cancellation criterion, the control unit 100 may determine whether the ignition is stopped at the time t max If not done by time t max You can specify that automatic cancellation occurs after

[0122] Figure 10 shows the relationship between t1 and t max 10 shows an alternative form of the first curve, which is defined between and increases linearly. This first curve therefore specifies that, over time, increasingly higher requirements are imposed on the determined differential rate Deltav in order to maintain the warning mode 213. If the differential rate Deltav falls below the specified solid line, this results in a cancellation (change to calibration mode 211). Corresponding example values ​​are represented by stars in FIG. 10.

[0123] According to the invention, the corresponding first curve can be structured in an arbitrarily complex manner. Figure 11 shows a case where the threshold is constant between times t1 and t2, and then decreases from t2 to t max 1 shows an example of an embodiment in which the

[0124] Figure 12 shows the time series between t=0 and t max11 shows an embodiment of a first curve defined between t and t and initially extending along the x-axis (differential velocity = 0). At time t1, the first curve rises sharply and then follows the course of the example shown in Fig. 11. However, in contrast to the situation shown there, cancellation can occur from the beginning (t = 0) if an acceleration occurs in the opposite direction to the originally measured acceleration, resulting in a differential velocity Delta below 0.

[0125] 13-18 show possible configurations of the second curve specifying a threshold over time that, when exceeded, causes a change to ignition mode 220. The corresponding differential speed is illustrated by the black diamond in FIG. 13. In one example embodiment, this results in airbag triggering. The curve in FIG. 13 is shown as a curve from t3 to t max and specifies a certain threshold. In one example embodiment, a trigger may occur only if further criteria are met (see, for example, the direction criteria already described, or the temperature criteria, or the criteria related to information provided by the vehicle bus, etc.).

[0126] Figure 14 shows the relationship between t3 and t max and a linearly increasing probability of the second curve, which is defined between . The airbag 70 will not fire unless a specified threshold is exceeded (see exemplary values ​​in the star shape).

[0127] Figure 15 shows the relationship between t3 and t max is constant within the first range from t3 to t4, and then from t4 to t max This shows the possibility of a second curve, which increases increasingly to

[0128] FIG. 16 shows roughly the same situation as FIG. 15, but here the second curve is t max rises much more sharply as it approaches , so that the gradient becomes (nearly) infinite.

[0129] Figure 17 shows that the second curve is max It is defined between t3 and t4, and then falls within the first range from t4 to tmax 10 shows an example of another embodiment in which the

[0130] Figure 18 shows the time series between t=0 and t max It is defined between t and t, which first decreases linearly from time t to time t, then remains constant until time t', and finally max 2 shows the possibility of a second curve that rises linearly up to . According to the invention, the individual first and second curves can be combined with each other in any desired manner. Ultimately, they define a corridor that causes the system to remain in warning mode 213. If the corridor is not met, the method continues in calibration mode 211, waiting for a new entry into warning mode 213. If the corridor is exceeded, ignition occurs, provided that no further trigger criteria remain to be met.

[0131] In some of the example embodiments described, the measured acceleration values ​​were mapped by the control unit 100 to associated acceleration values ​​adr along the measurement direction based on the available information (angles α, β and γ) and taking into account the selected configuration (y acceleration sensor aligned parallel or coaxially with the vehicle's lateral axis yF) (see FIG. 21).

[0132] In another example embodiment, the calculated acceleration value adr (in the horizontal plane) can be used instead of the acceleration value adr (along the direction of travel in the vehicle plane) (FIG. 20). This is indicated when the angle γ, or generally the orientation of the sensor unit 74 relative to the vehicle plane, cannot be definitively determined.

[0133] The invention has been described above in relation to protective means in the form of a gas generator, e.g., an airbag, which is inflated using a pyrotechnic cartridge. Other (active) protective means can also be used according to the invention, such as belt tensioners, which are operated by an electric motor or by pyrotechnic means. The gas generator can also be designed as a pressure accumulator, e.g., as a cartridge with a pressurized propellant.

[0134] However, the present invention can also be implemented with several calculated acceleration values ​​aX, aY, aZ, each determined based on measured acceleration values ​​rawX, rawY and rawZ.

[0135] A number of methods for triggering (active) protection measures have been described above. This means that the methods are basically suitable for triggering various protection measures. This does not mean that the methods are implemented in such a way that they trigger several protection measures in specific individual cases or that they can trigger several protection measures simultaneously or one after the other. Rather, the triggering of a single protection measure is sufficient to implement the method according to the invention.

[0136] In this respect, it should be noted that all of the above-mentioned parts taken individually and in any combination, and in particular the details shown in the drawings, are claimed as further embodiments of the invention, variations of which are possible.

[0137] In this respect, it is also pointed out that all of the above-mentioned parts or features, individually in each case and even without additionally mentioned features in the respective context, even if they are not individually and explicitly specified as optional features in the respective context, for example by using "in particular", "preferably", for example, "optionally", parentheses (), etc., or in combination or any subcombination, are to be considered as independent embodiments or further developments of the invention as defined in particular in the introduction and claims of this specification. Departures from this are also possible. In particular, it is pointed out that the word "in particular" or parentheses () are intended to explicitly characterize features that are not essential in the respective context.

[0138] Finally, it is pointed out that the present application seeking protection (and, in the case of registration or grant, protection of the invention) aims at the widest possible scope of protection for the invention, and this should be borne in mind when reading, especially as far as (inter)generalizations of explicitly disclosed features or combinations of features are concerned.

[0139] [Technical idea disclosed in this specification] [Item 1] A method for triggering a protection means, in particular an airbag and / or a belt tensioner, in a child restraint system in particular according to one of items 18 to 20, comprising: a) determining at least one measurement direction and / or one measurement direction corridor; b) receiving acceleration sensor signals from at least two acceleration sensors (74x, 74y, 74z), preferably oriented in different directions; c) calculating at least one first acceleration value (aX) along the measurement direction and / or within the measurement direction corridor; d) determining a trigger signal based on at least the at least one first acceleration value (aX); e) triggering at least one protection measure based on said trigger signal; A method comprising:

[0140] [Item 2] Item 1, a method according to item 1, characterized in that a plurality of acceleration values, in particular a first acceleration value (aX), are determined / calculated over time. [Item 3] 3. The method according to claim 1 or 2, characterized in that a warning mode is adopted when at least one warning criterion is met, preferably when the acceleration value, in particular the first acceleration value (ax), exceeds a threshold value.

[0141] [Item 4] in said warning mode, at least one trigger criterion is (repeatedly) checked, said trigger criterion or one of said at least one trigger criterion being based on at least one acceleration value (ax, ay, az), in particular an acceleration value based on a differential velocity (Deltav) calculated on the basis of said at least one acceleration value, and / or varying over time; 10. The method according to claim 3, wherein the protection means are triggered when the at least one trigger criterion is met in the warning mode.

[0142] [Item 5] In the warning mode, at least one cancellation criterion is (repeatedly) checked, and the warning mode is terminated when at least one of the cancellation criteria is fulfilled, the cancellation criterion being: i) time-out, in particular exceeding the maximum time interval (tmax) since said warning mode was (last) entered, and / or ii) exceeding the maximum number of calculation steps, in particular calculation step c), and / or iii) the acceleration value, in particular the first acceleration value (ax), is below a threshold value; and / or iv) the calculated delta velocity (DeltaV) or one of the delta velocities is below a threshold value; 5. The method according to any one of the preceding items, in particular item 4, characterized in that it comprises:

[0143] [Item 6] 6. The method according to one of the preceding items, in particular item 4 or 5, characterized in that at least one of the cancellation criteria, in particular the cancellation criterion iv, varies over time, the start of which (t0) is preferably set as the time when the warning mode was (last) entered. [Item 7] The method according to one of the preceding items, characterized in that in the calibration step a reference plane is determined using a gravity vector, in particular gravity (g), which is preferably determined using the acceleration sensor signal, and the measurement direction or the measurement direction corridor is determined using the reference plane.

[0144] [Item 8] 10. The method according to claim 7, wherein the reference plane is a vehicle plane, preferably comprising a direction of a driving vector, and the vehicle plane is preferably determined using an input, in particular an angle of inclination. [Item 9] The method according to one of the preceding items, in particular item 8, characterized in that the gravity vector and / or the reference plane are determined using a plurality of acceleration sensor signals, in particular a plurality of acceleration sensor signals of a first acceleration sensor (74x) and a plurality of acceleration sensor signals of a third acceleration sensor (74z).

[0145] [Item 10] the gravity vector and / or the reference plane are continuously and / or iteratively updated; and / or The calibration step is performed continuously and / or iteratively. The method according to one of the preceding items, in particular items 8 and 9, characterized in that [Item 11] 10. The method according to claim 9, wherein at least one sleep mode criterion is determined, in particular using the acceleration value, and when the at least one sleep mode criterion is present, a sleep mode is adopted, and in the sleep mode, the acceleration value, in particular the first acceleration value (ax), is determined at a (predetermined) first frequency that is smaller than a second frequency assigned to a non-sleep mode.

[0146] [Item 12] 1. A method, in particular according to one of items 1 to 11, for triggering a protection means, in particular an airbag and / or a belt tensioner, in a child restraint system, in particular according to one of items 18 to 20, comprising: a) receiving an acceleration sensor signal from at least one acceleration sensor (74x, 74y, 74z); b) calculating at least one differential velocity (Deltav) using said acceleration sensor signal; c) determining a trigger signal based on at least said at least one differential velocity (Delta); d) triggering at least one protection measure based on said trigger signal; A method comprising:

[0147] [Item 13] 1. A method, in particular according to one of items 1 to 12, for triggering a protection means, in particular an airbag and / or a belt tensioner, in a child restraint system, in particular according to one of items 18 to 20, comprising: a) receiving a first acceleration sensor signal from at least one acceleration sensor (74x, 74y, 74z); b) determining, preferably iteratively, at least one measurement direction and / or measurement direction corridor based on the first acceleration sensor signal; c) receiving a second acceleration sensor signal from the at least one acceleration sensor (74x, 74y, 74z); d) determining a trigger signal based on at least the second acceleration sensor signal, preferably using the iteratively determined measurement corridor or the measurement direction; e) triggering at least one protection measure based on said trigger signal; A method comprising:

[0148] [Item 14] 1. A method, in particular according to one of items 1 to 13, for triggering a protection means, in particular an airbag and / or a belt tensioner, in a child restraint system, in particular according to one of items 18 to 20, comprising: a) determining at least one measurement direction and / or measurement direction corridor; b) receiving an acceleration sensor signal from at least one acceleration sensor (74x, 74y, 74z); c) calculating at least one first acceleration value; d) comparing said at least one first acceleration value with said measurement direction and / or said measurement direction corridor; e) determining a trigger signal based at least on a result of said comparison; f) triggering at least one protection measure based on said trigger signal; A method comprising:

[0149] [Item 15] 1. A method, in particular according to one of items 1 to 14, for triggering a protection means, in particular an airbag and / or a belt tensioner, in a child restraint system, in particular according to one of items 18 to 20, comprising: a) checking a condition for entering a standby mode, said condition being: - the correct connection of said child restraint device to the vehicle seat; - detection of a child in a car seat; - correct fixation of the child in the restraint device; - correct installation of the support feet of said restraint device a checking step including at least one of the following conditions: b) receiving an acceleration sensor signal from at least one acceleration sensor (74x, 74y, 74z); c) determining a trigger signal based on at least one acceleration value and / or the acceleration sensor signal; d) triggering at least one protection measure based on said trigger signal; A method comprising:

[0150] [Item 16] A computer-readable memory having instructions for performing the method of one of items 1 to 15 when executed on at least one computing unit. [Item 17] A control and regulation unit adapted (in operation) to carry out the method according to at least one of items 1 to 15.

[0151] [Item 18] A child restraint system, in particular a child car seat (10) and / or an impact shield (50), or a component of such a system, for installation in a vehicle, having a longitudinal axis (xS), a lateral axis (yS) and a vertical axis (zS), comprising: - at least one (active) protection means, in particular an airbag with at least one inflatable gas bag (71), - at least one drive unit, in particular a gas generator (72), for activating said at least one protection means; - at least one control unit for activating said drive unit by means of a trigger signal, preferably for carrying out the method according to one of items 1 to 15; at least one sensor unit having a first acceleration sensor (74x) and a third acceleration sensor (74z) for outputting a first acceleration sensor signal and a third acceleration sensor signal, respectively; Equipped with The control unit preferably receives the acceleration sensor signals and determines whether the drive unit is activated based on the first acceleration sensor signal and the third acceleration sensor signal.

[0152] [Item 19] Item 19. A child restraint device or component of such a device according to item 18, comprising primary and secondary sensor units (74) each having at least two acceleration sensors, preferably three acceleration sensors (74x, 74y, 74z), and preferably the acceleration sensors (74x, 74y, 74z) of the primary sensor units are sampled at a higher rate than the acceleration sensors of the secondary sensor units. [Item 20] the first acceleration sensor (74x) and the third acceleration sensor (74z) are for detecting a first acceleration value (rawx) and a third acceleration value (rawz), respectively, in detection directions extending at least substantially in or parallel to a plane subtended by the vertical axis (zS) and the longitudinal axis (xS) of the child restraint; and / or the first acceleration sensor (74x) and the third acceleration sensor (74z) are arranged at least substantially orthogonal to each other; and / or a second acceleration sensor (74y) arranged at least substantially parallel or coaxial with said lateral axis; and / or 20. A child restraint device or component of such a device according to item 18 or 19, characterized in that the first acceleration sensor (74x) for detecting the first acceleration value (rawx) is arranged in one / said detection direction having an angle of more than 5° and / or less than 30° relative to the longitudinal axis of the vehicle.

[0153] [Item 21] 21. A child restraint device or component of such a device according to any one of items 18 to 20, comprising at least one energy store, in particular a battery, for supplying the control unit and / or the gas generator. [Item 22] The protection means comprises at least one airbag having at least one inflatable gas bag (71); a) the gas bag (71) is convertible from an uninflated state to an inflated state; and / or b) the gas bag (71) is at least substantially folded in the uninflated state; and / or c) the outer surface of the gas bag (71) in the uninflated state of the gas bag (71) is such that over a maximum of 25% of the outer surface, each outer surface intersects the outer surface perpendicularly at a second point on the outer surface; and / or 22. A child restraint system or component of such a system according to one of items 18 to 21, characterized in that in the uninflated state of the at least one gas bag (71), a maximum of 25% of the outer surface of the gas bag is in direct contact with another part of the outer surface.

[0154] [Item 23] A child restraint system or component of such a system according to one of items 18 to 22, in particular item 22, characterized in that at least one pressure limiting device is associated with the gas bag (71) in such a way that, when a predetermined pressure is reached or exceeded at least locally, pressure is relieved by gas escaping from the gas bag (71), said pressure relief upon release preferably taking place at least in the lower and / or rear region of the gas bag (71) and / or at the edge of the gas bag (71).

[0155] [Item 24] the at least one gas bag (71) in the inflated state has a thickness of at most 30 cm, preferably at most 18 cm, and / or is at least substantially flat, in particular has a thickness that is less than its extent in at least one direction perpendicular to the thickness direction, and / or is at its furthest point away from the rest of the components of the child restraint or child high-speed device by at most 30 cm, preferably at most 18 cm; and / or A child restraint device or component of such a device according to one of items 18 to 23, in particular according to item 22 or 23, characterized in that the at least one airbag (71) in the inflated state has an internal volume of at most 20 liters, preferably at most 12 liters and / or at least 1 liter, preferably at least 3 liters. [Explanation of symbols]

[0156] 10...child seat, 20...main body, 21...seat section, 21R...right side (of seat section), 21L...left side (of seat section), 21B...bottom / lower side (of seat section), 21M...center section (of seat section), 22...backrest, 23...side wing / side bolster, 24...headrest, 25...support foot, 26...upper tether, 28...fastening device (e.g., Isofix), 29...side impact protection, 50...impact sheet 52...left impact shield section, 53...right impact shield section, 54...fixed section (of impact shield), 55...buffer (of impact shield), 57...cover, 58...first section, 59...second section, 70...airbag, 71...gas bag, 72...gas generator, 74...sensor unit, 74x...x-axis sensor, 74y...y-axis sensor, 74z...z-axis sensor, 77...steering device, 78...proximal section, 7 9...distal compartment, 80...gas outlet, 81...gas inlet, 82...sealing, 83, 83'...coupling means, 84...channel, 90...base, 90B...bottom / underside (of base), 92...support foot, 100...control unit, 102...memory, 104...computing unit, 106...interface, 200...lock mode, 210...standby mode, 211...calibration mode, 213...warning mode, 215...sleep mode, 22 0...Ignition mode, rawX...Measured acceleration value (X axis), rawY...Measured acceleration value (Y axis), rawZ...Measured acceleration value (Z axis), aX...Calculated acceleration value (X axis), aY...Calculated acceleration value (Y axis), aZ...Calculated acceleration value (Z axis), xS, yS, zS...Longitudinal, lateral, and vertical axes of the child seat, xF, yF, zF...Longitudinal, lateral, and vertical axes of the vehicle, Deltav...Differential velocity

Claims

1. A method for triggering a protective means in a child restraint system, comprising: a) determining at least one measurement direction and / or one measurement direction corridor; b) receiving acceleration sensor signals from at least two acceleration sensors (74x, 74y, 74z); c) calculating at least one first acceleration value (aX) along the measurement direction and / or within the measurement direction corridor; d) determining a trigger signal based on at least said at least one first acceleration value (aX); e) triggering at least one protection means based on said trigger signal; A method comprising:

2. 2. The method of claim 1, wherein a plurality of acceleration values ​​are determined / calculated over time.

3. 2. The method of claim 1, wherein the warning mode is adopted when at least one warning criterion is met.

4. in said warning mode, at least one trigger criterion is repeatedly checked, said trigger criterion or one of said at least one trigger criterion being based on at least one acceleration value (ax, ay, az) and / or varying over time; 4. The method of claim 3, wherein the protection measures are triggered when the at least one trigger criterion is met in the warning mode.

5. In the warning mode, at least one cancellation criterion is repeatedly checked, and the warning mode is terminated when at least one of the cancellation criteria is satisfied, the cancellation criterion being: i) timeout, and / or ii) exceeding the maximum number of calculation steps; and / or iii) the acceleration value falls below a threshold; and / or iv) a differential velocity (DeltaV) calculated based on at least one acceleration value, or one of said differential velocities, is below a threshold value; 5. The method of claim 4, comprising:

6. The method of claim 5 , wherein at least one of the cancellation criteria varies over time.

7. 2. The method of claim 1, wherein in the calibration step, a reference plane is determined using a gravity vector, and the measurement direction or the measurement direction corridor is determined using the reference plane.

8. 8. The method of claim 7, wherein the reference plane is a vehicle plane that includes a direction of a driving vector, the vehicle plane being determined using an input.

9. 9. The method of claim 8, wherein the gravity vector and / or the reference plane are determined using a plurality of acceleration sensor signals.

10. the gravity vector and / or the reference plane are continuously and / or iteratively updated; and / or The calibration step is performed continuously and / or iteratively.

9. The method according to claim 8.

11. 2. The method of claim 1, wherein at least one sleep mode criterion is determined, and when said at least one sleep mode criterion is present, a sleep mode is adopted, and in said sleep mode, acceleration values ​​are determined at a predetermined first frequency that is lower than a second frequency assigned to a non-sleep mode.

12. 1. A method for triggering a child restraint system, comprising: a) receiving an acceleration sensor signal from at least one acceleration sensor (74x, 74y, 74z); b) calculating at least one differential velocity (Delta) using the acceleration sensor signal; c) determining a trigger signal based at least on said at least one differential velocity (Delta); d) triggering at least one protection means based on said trigger signal; A method comprising:

13. 1. A method for triggering a child restraint system, comprising: a) receiving a first acceleration sensor signal from at least one acceleration sensor (74x, 74y, 74z); b) determining at least one measurement direction and / or measurement direction corridor based on the first acceleration sensor signal; c) receiving a second acceleration sensor signal from the at least one acceleration sensor (74x, 74y, 74z); d) determining a trigger signal based on at least the second acceleration sensor signal; e) triggering at least one protection means based on said trigger signal; A method comprising:

14. 1. A method for triggering a child restraint system, comprising: a) determining at least one measurement direction and / or measurement direction corridor; b) receiving an acceleration sensor signal from at least one acceleration sensor (74x, 74y, 74z); c) calculating at least one first acceleration value; d) comparing said at least one first acceleration value with said measurement direction and / or said measurement direction corridor; e) determining a trigger signal based at least on a result of said comparison; f) triggering at least one protection means based on said trigger signal; A method comprising:

15. 1. A method for triggering a child restraint system, comprising: a) checking a condition for entering a standby mode, said condition being: - the correct connection of the child restraint system to the vehicle seat; - detection of a child in said child seat; - correct fixation of the child in the restraint device; - correct placement of the support feet of the restraint device; a checking step including at least one condition of b) receiving an acceleration sensor signal from at least one acceleration sensor (74x, 74y, 74z); c) determining a trigger signal based on at least one acceleration value and / or the acceleration sensor signal; d) triggering at least one protection means based on said trigger signal; A method comprising:

16. A computer readable memory having instructions for performing the method according to one of claims 1 to 15 when executed on at least one computing unit.

17. A control and regulation unit adapted to carry out the method according to at least one of claims 1 to 15 when in operation.

18. 1. A child restraint system for installation in a vehicle, the child restraint system having a longitudinal axis (xS), a lateral axis (yS), and a vertical axis (zS), the child restraint system comprising: - at least one active protection means; at least one drive unit for activating said at least one active protection means; - at least one control unit for activating said drive unit by means of a trigger signal in order to carry out the method according to one of claims 1 to 15; at least one sensor unit having a first acceleration sensor (74x) and a third acceleration sensor (74z) for outputting a first acceleration sensor signal and a third acceleration sensor signal, respectively; Equipped with The control unit determines whether the drive unit is activated based on the first acceleration sensor signal and the third acceleration sensor signal.

19. 20. The child restraint system of claim 18, comprising primary and secondary sensor units (74) each having at least two acceleration sensors, the acceleration sensors (74x, 74y, 74z) of the primary sensor units being sampled at a higher rate than the acceleration sensors of the secondary sensor units.

20. the first acceleration sensor (74x) and the third acceleration sensor (74z) are for detecting a first acceleration value (rawx) and a third acceleration value (rawz), respectively, in detection directions extending at least substantially in or parallel to a plane subtended by the vertical axis (zS) and the longitudinal axis (xS) of the child restraint; and / or the first acceleration sensor (74x) and the third acceleration sensor (74z) are arranged at least substantially orthogonal to each other; and / or a second acceleration sensor (74y) arranged at least substantially parallel or coaxial with said lateral axis; and / or 19. A child restraint system as described in claim 18, characterized in that the first acceleration sensor (74x) for detecting the first acceleration value (rawx) is arranged in one / said detection direction having an angle of more than 5° and / or less than 30° with respect to the longitudinal axis of the vehicle.

21. 20. A child restraint system as claimed in claim 18, comprising at least one energy store for supplying the control unit and / or the gas generator.

22. said at least one active protection means comprising at least one airbag having at least one inflatable gas bladder (71); a) said gas bag (71) is convertible from an uninflated state to an inflated state; and / or b) said gas bag (71) is at least substantially folded in said uninflated state; and / or c) the outer surface of the gas bag (71) in the uninflated state of the gas bag (71) is such that over a maximum of 25% of the outer surface, each outer surface intersects the outer surface perpendicularly at a second point on the outer surface; and / or 19. A child restraint system as claimed in claim 18, characterized in that in the uninflated state of the at least one gas bag (71), up to 25% of the outer surface of the gas bag is in direct contact with another portion of the outer surface.

23. 23. A child restraint system as claimed in claim 22, characterized in that at least one pressure limiting device is associated with the gas bag (71) so that pressure is relieved by gas escaping from the gas bag (71) when a predetermined pressure is reached or exceeded at least locally, and that the pressure relief upon release occurs at least in the lower and / or rear region of the gas bag (71) and / or at the edge of the gas bag (71).

24. the at least one gas bag (71) in the inflated state has a thickness of at most 30 cm, and / or is at least substantially flat and has a thickness that is less than its extent in at least one direction perpendicular to the thickness direction, and / or the furthest point from the rest of the components of the child restraint or child high-speed device is at most 30 cm away, and / or 23. A child restraint system according to claim 22, characterized in that the at least one airbag (71) in the inflated state has an internal volume of up to 20 litres.

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