Patent Grant
11034318
Vehicles such as aircraft include safety response devices that actively respond to critical events such as acceleration impulses to provide or assist passenger or equipment security and safety. Typical safety response devices include airbags, backrest breakover mechanism, belt pretensioners, etc. Many safety response devices, such as airbags, are one-time-use devices, and their deployment is disruptive to passengers and expensive to replace to travel services operators such as airline companies. As such, needless activation of safety response devices is to be avoided.
For example, an airbag may be deployed when an acceleration threshold magnitude is exceeded. However, acceleration impulses of very short duration may require no response. Such spurious impulses may be caused by passengers slamming stowage compartment doors or impacting seats with luggage as they enter and exit a passenger seating area.
Different types of safety devices and varying installations of safety devices call for flexibility in a triggering system. Particularly, time characteristics of spurious acceleration events are to be discriminated and critical inertial events, for which a response is needed, need to be discerned.
Accordingly, what is needed is a triggering system for appropriately activating at least one safety response device
To achieve the foregoing and other advantages, the inventive aspects disclosed herein are directed to a triggering system for activating at least one safety response device. At least one acceleration sensor is operative to output a signal for a time duration in which an acceleration impulse exceeds an acceleration magnitude threshold. A first switching device electrically connected to the acceleration sensor is operative to, upon receiving the signal output by the acceleration sensor, electrically connect a power supply to at least one safety response device for the time duration. A time delay device electrically connected to the acceleration sensor, the time delay device is operative to, upon completion of a delay time after receiving the signal output by the acceleration sensor, output a signal for the time duration. A second switching device electrically connected to the time delay device is operative to, upon receiving the signal output by the time delay device, electrically connect the power supply to the at least one safety response device for the time duration. When the time duration exceeds the delay time, the first switching device and the second switching device concurrently electrically connect the safety response device to the power supply, thereby activating the safety response device.
In some embodiments, the time delay is adjustable.
In some embodiments, a second acceleration sensor electrically is connected in series to the at least one acceleration sensor. The sensors are operative together to output the signal for the time duration in which an acceleration impulse exceeds concurrently a respective acceleration magnitude threshold of each sensor.
In some embodiments, multiple safety response devices include the at least one safety response device.
In some embodiments, the second switching device includes multiple switches in specific correspondence and respective electrical communication with the safety response devices.
In some embodiments, the multiple switches are switched from non-conducting conditions to conducting conditions when the second switching device receives the signal output by the time delay device.
In some embodiments, an indicator electrically connected to the first and second switching devices is operative to indicate at least one status.
In some embodiments, the power supply includes a battery, and the trigger system consumes essentially no power from the battery in a standby mode in which no acceleration impulse exceeds the acceleration magnitude threshold.
In some embodiments, the acceleration sensor is generally maintained in a non-conducting condition, and achieves a conducting condition when actuated by an acceleration impulse exceeds the acceleration magnitude threshold.
In some embodiments, the acceleration sensor returns to the non-conducting condition when the acceleration impulse reduces below the acceleration magnitude threshold.
In some embodiments, the safety response device includes an electrically ignited pyrotechnic charge.
In some embodiments, the safety response device includes an airbag inflated when activated.
In some embodiments, the safety response device includes a pretensioner that rapidly retracts a shoulder belt when activated.
In some embodiments, the safety response device includes a breakover mechanism for the backrest of a passenger seat assembly to permit or provide breakover when activated.
In another aspect, the inventive concepts disclosed herein are directed to a method of activating at least one safety-response device. The method includes: activating at least one acceleration sensor; detecting, by the at least one acceleration sensor, an acceleration impulse; initiating, upon detecting the acceleration impulse, a time delay; determining, upon expiration of the time delay, whether the acceleration impulse is still detected; and triggering at least one safety response device upon determining that the acceleration impulse is still detected upon expiration of the time delay.
In some embodiments, detecting, by the at least one acceleration sensor, an acceleration impulse includes passing a signal through at least two acceleration sensors in series connection.
In some embodiments, determining whether the acceleration impulse is still detected includes: sending an undelayed output of the acceleration sensor to a first switching device; sending a delayed output of the acceleration sensor to a second switching device; and determining whether the undelayed and delayed outputs of the acceleration sensor are concurrent at the first switching device and second switching device.
In some embodiments, determining whether the acceleration impulse is still detected includes determining a duration of the acceleration impulse is greater than the time delay.
In some embodiments, detecting, by the at least one acceleration sensor, an acceleration impulse, includes the acceleration sensor being actuated from a non-conducting condition to a conducting condition by acceleration greater than a predetermined magnitude threshold.
In some embodiments, triggering at least one safety response device includes triggering an airbag to inflate.
In some embodiments, triggering at least one safety response device causes an electrically ignited pyrotechnic charge to fire.
Embodiments of the inventive concepts may include one or more or any combination of the above aspects, features and configurations.
Implementations of the inventive concepts disclosed herein may be better understood when consideration is given to the following detailed description thereof. Such description makes reference to the included drawings, which are not necessarily to scale, and in which some features may be exaggerated, and some features may be omitted or may be represented schematically in the interest of clarity. Like reference numbers in the drawings may represent and refer to the same or similar element, feature, or function. In the drawings:
The description set forth below in connection with the appended drawings is intended to be a description of various, illustrative embodiments of the disclosed subject matter. Specific features and functionalities are described in connection with each illustrative embodiment; however, it will be apparent to those skilled in the art that the disclosed embodiments may be practiced without each of those specific features and functionalities. The aspects, features and functions described below in connection with one embodiment are intended to be applicable to the other embodiments described below except where expressly stated or where an aspect, feature or function is incompatible with an embodiment.
Circuits, devices, systems, and methods are described in the following for adjustably delaying the response of one or more safety devices following a potential triggering event such as the receipt of a signal from a sensor. Time delays are predetermined to prevent the triggering of safety response devices when momentary false or spurious sensor signals are received due to, for example, equipment vibrations, minor impacts or accelerations, and other undiagnosed events for which no safety device response is needed. The described can be utilized to compensate for timing differences among various types of sensors and safety response devices, permitting for example to a triggering system to be used with a variety of sensor types and in a variety of applications. Where the actions of sensors and safety response devices have individualized timing characteristics, for example within a respective tolerance as specified by a manufacturer or as determined by empirical testing, those actions can be coordinated using an adjustable delay to avoid falsely triggering safety systems and to assure properly timed response sequences when safety systems are triggered by critical conditions such as inertial events, referring to occurrences of relatively high acceleration.
Furthermore, these descriptions refer to the DC power supply 102 side of the triggering system 100 as generally upstream and the safety response devices 110 as generally downstream without necessarily referring to electrical current flow directions, which are typically defined as opposite the direction of electron flow in a circuit or conductor segment. In that sense, the high-side path 104 and low-side path 106 have respective upstream and downstream portions delineated by switching devices that selectively propagate voltage “signals” from the power supply 102 downstream to the safety response devices 110.
It should also be understood that physical implementations of safety-response triggering systems according to
Additionally, the term signal is broadly used herein to refer to connectivity as in closed circuit conditions for voltage propagation and current flow. In that sense, for example, a battery can be described as providing a signal to a switch, and when the switch is in a conducting condition, the switch propagates the signal from the battery to downstream devices.
In
A switch control subsystem 130, which includes an inertial switch circuit 132 and a delay device 134, controls the connectivity status of the high-side and low-side switching devices 112 and 122. Upstream of the switching devices, the inertial switch circuit 132 includes at least one sensor, such as an acceleration sensor operative to detect an acceleration impulse. Two sensors are illustrated and referenced as a first sensor 136 and a second sensor 138 representing that any number of sensors can be included. The two sensors 136 and 138 are illustrated arranged in an electrical series connection or relation to each other to provide the assurance of redundancy in any connectivity or signal conveyed by the inertial switch circuit 132. The inertial switching circuit 132 can include the sensors and drive circuitry according to the type of sensors used.
The sensors 136 and 138 are operative to detect changes in velocity of structures to which the sensors are connected or coupled, such as the components of passenger seats, the structures in an aircraft passenger cabin, or other structures of the aircraft overall such as fuselage and frame elements. The sensors are operative to detect high G-force events and may include any combination of multi-axis accelerometers, gyroscopes, and magnetometers, among others. In some implementations, accelerometers may be configured measure an amount of acceleration in a particular direction, gyroscopes may be configured to measure changes in orientation or relative velocity, and magnetometers measure changes in magnetic fields that can be used to determine absolute orientation of the elements to which the magnetometers are connected. Because accelerometers, gyroscopes, and magnetometers may be used to measure different features of inertial movement, the sensor outputs may be combined into or may otherwise contribute to connectivity or an output emitted or generated by the inertial switch circuit 132.
In a particular conceived example, the first and second sensors 136 and 138 are ball and spring type acceleration switches that are generally maintained in a non-conducting condition in which a spring biases a ball from a conducting position. Such switches achieve electrically conducting conditions when actuated by acceleration greater than a predetermined magnitude threshold and return to non-conducting condition when the acceleration reduces below the threshold. The magnitude threshold of each such sensor can be predetermined, for example, by the spring constant of the spring and by the geometry of the device. In such a device, the ball, serving as an inertial mass, moves against the force of the spring to a conducting position to provide connectivity by either direct conduction through the ball or by otherwise engaging or actuating a switch with the ball during an inertial event. Thus, the magnitude threshold can be predetermined by selection of the acceleration sensors used or by adjustment of an acceleration sensors. The benefit of the series connection of two or more sensors that respond to an inertial incident is that a signal or connectivity is passed through the series connection only when all sensors in the signal path are in a conducting condition concurrently responding to an acceleration event.
An upstream input 140 of the inertial switch circuit 132 is electrically connected to the DC power supply 102 by way of the upstream portion 114 of the high-side path 104. Upon actuation of all series connected sensors in the inertial switch circuit 132, connectivity from the input to the outputs of the inertial switch circuit 132 is provided by the inertial switch circuit 132. A first output 142 of the inertial switch circuit 132 is routed or connected to the high-side switching device 112. A second output 144 of the inertial switch circuit 132 is routed or connected to the adjustable delay device 134, and, downstream of the delay device 134, to the low-side switching device 122.
An upstream first input 146 of the low-side switching device 122 is electrically connected to the DC power supply 102 by the upstream portion of the low-side path 106. A second input 148 of the low-side switching device 122 is electrically connected to the output 150 of the delay device 134. An output of the low-side switching device 122 is routed to the downstream safety response devices 110 by the downstream portion 126 of the low-side path 106. The low-side switching device 122 is represented in
The downstream portion 126 of the low-side path 106 can be a single conductance path as expressly illustrated in
An upstream first input 118 of the high-side switching device 112 is electrically connected to the DC power supply 102 by the upstream portion 114 of the high-side path 104. A second input 120 of the high-side switching device 112 is electrically connected to the first output 142 of the inertial switch circuit 132. An output of the high-side switching device 112 is routed to the downstream safety response devices 110 by the downstream portion 116 of the high-side path 104. The high-side switching device 112 is generally maintained in a non-conducting condition between the upstream portion 114 and downstream portion 116 of the high-side path 104. However, upon receipt of connectivity or signal from the first output 142 of the inertial switch circuit 132, the high-side switching device 112 is switched to a conducting condition.
The high-side switching device 112, in at least one embodiment similar to the low-side switching device 122, has multiple gated switches, each of which is in specific correspondence and electrical communication with a downstream safety response device 110. Other embodiments of at least the high-side switching device 112 are within the scope of these descriptions. In any embodiment, switchable connectivity from the power supply device 102 to each safety response device 110 is provided along the high-side path 104 by the high-side switching device 112 under control of the switch control subsystem 130, and along the low-side path 106 by the low-side switching device 122 under control of the switch control subsystem. Advantageous individually switched control of each safety response device 110 can be provided by both or either one of the low-side switching device 122 and high-side switching device 112. In the illustrated embodiment of the safety-response triggering system 100, the low-side switching device 122 is expressly illustrated as having multiple gated switches 154 in one-to-one correspondence and electrical communication with the safety response devices 110 to represent that at least the low-side switching device 122 provides the advantageous individual switched control of each safety response device or groupings thereof.
The delay device 134 generally receives a signal from the second output 150 of the inertial switch circuit 132 and subsequently, at the expiration of a time delay, propagates the signal, or sends a corresponding generated signal, to the low-side switching device 122 prompting a conducting condition from the upstream portion 124 to the downstream portion 126 of the low-side path 106. The counting of the time delay is initiated upon receipt of the signal from the inertial switch circuit 132. The time delay has an adjustable duration. Thus, the signals sent by the delay device 134 to the low-side switching device 122 lag the signals received from the inertial switch circuit 132 by the adjustable time delay. The time delay can be adjusted, for example, by modifying the values of resistors during post production testing to assure a desired predetermined time delay in accordance with the particular safety response devices 110 used and how they are to be utilized.
The safety response devices 110 are activated or triggered when the low-side switching device 122 and high-side switching device 112 are concurrently in conducting condition, permitting connectivity concurrently along the high-side path 104 and low-side path 106. This defines a completed circuit from the power supply 102 to the safety response devices 110, applying a voltage differential to the safety response devices 110 thereby activating the safety response devices 110. The delay device 134 introduces a time delay in the second input 148 of the low-side switching device 122 relative to the second input 120 of the high-side switching device 112 to prevent the triggering of safety response devices 110 in the event of momentary false or spurious signals at the outputs of the inertial switch circuit 132. Any connectivity or signal initiated at the inertial switch circuit 132 having a duration less than the time delay introduced by the delay device 134 will result in non-concurrent signals at the second inputs of the low-side and high-side switching devices due to expiration of the signal at the high-side switching device 112 before expiration of the time delay, preventing the safety response devices 110 from activating.
The multiple safety response devices 110 may be triggered at once or in a desired sequence individually or in groups thereof. The safety response devices 110 as illustrated in an array 156 in
The safety response devices 110 may be breakover mechanisms for the backrests of passenger seat assemblies to permit or provide breakover when an inertial event causes a passenger to lunge toward or impact a seatback from behind. Forward breakover movement of the seatback preceding or in response to a passenger impact may dissipate energy and reduce injuries. See, for example, US patent application publication US 2018/0346125 A1, entitled “Seat Back Breakover with Dynamically Triggered Actuator,” published Dec. 6, 2018, which is incorporated herein, for further detailed information regarding breakover mechanisms, acceleration sensor, drive circuitries, and actuators used with or implemented upon aircraft passenger seats.
The safety response devices 110 may be active pretensioners that rapidly retract shoulder belts, in the event of a sudden deceleration of an aircraft, to substantially remove slack between a passenger and the shoulder belt. See, for example, US patent application publication US 2017/0283079 A1, entitled “Pretensioner for Retractable Shoulder Belt and Seat Belt,” published Oct. 5, 2017, which is incorporated herein, for further detailed information regarding pretensioners.
In a particularly conceived example, the safety response devices 110 are airbag devices including squibs that produce gas pressure or release previously pressurized gas to inflate airbags. The airbag devices may be used in vehicles such as aircraft. Airbags may be deployed from one or more passenger seat assemblies, structures in a passenger cabin environment, or one or more components of a single seat assembly. Airbags may be deployed forward of a passenger and along both lateral sides. Multiple airbag devices represented by the safety response devices 110 shown in
An indicator 160 may be provided, as shown in
A diagnostics subsystem 162 can also be provided, as represented in
By adjustment of the time delay introduced by the delay device 134, the triggering system 100 can be used in various applications and with various safety response device types, all with differing time requirements. Also, various types of acceleration switches can be used in the inertial switching circuit 132 and their varying time response functions, by which spurious events are to be discriminated to prevent unwanted safety response device activation, can be accommodated by adjustment of the time delay. The adjustable time delay defines a duration threshold, predetermined by adjustment, by which a critical inertial event is determined and by which acceleration impulses of lesser duration are discriminated. Any connectivity or signal initiated at the inertial switch circuit 132 having a duration less than the time delay will result in non-concurrent signals at the switching devices, preventing the safety response devices 110 from activating. The triggering system 100 provides an alternative and safer approach relative to firing an airbag, for example, at a threshold acceleration magnitude regardless of duration.
The inertial switch circuit 132 discriminates against acceleration impulses below a predetermined magnitude threshold. The time delay device 134, cooperatively with the low-side switching device 122 and high-side switching device 112, discriminates against acceleration impulses that are shorter-lived than an adjustable duration threshold. Thus, the safety-response devices 110 are activated only when a critical inertial event is determined according to the magnitude and duration thresholds, while discriminating against lesser magnitude and duration acceleration impulses. The triggering system 100 therefore effectively filters outs short time vibrations caused by minor incidental impacts and other non-impact related accelerations while assuring the triggering system 100 responds to critical inertial events with a predetermined response by activating the safety response devices 110.
The triggering system as illustrated can advantageously be battery powered and consumes no power from the battery in standby mode, referring to quiescence in which no acceleration impulses exceed the magnitude thresholds of the acceleration sensors at the inertial switching circuit 132. The triggering system can thus have a long service life after installation assuming no or few critical inertial events occur.
General activation of a safety system including at least one sensor and at least one safety response device is represented at step 202 as “START.” Upon activation, at least one sensor is ready to detect a change in status. For example, where the sensor is an acceleration sensor, the sensor is ready at “START” to detect an acceleration impulse. A sensor 136 and/or 138 (
The method 200 is described herein with reference also to the system 100 of
With at least one sensor in an active sensing mode following step 202, whether an acceleration impulse is detected is determined in step 204. In the absence of a detected acceleration impulse, represented as a “NO” return branch 206 in
In the presence of an acceleration impulse detected as determined at step 204, the method 200 continues, represented as a “YES” in
For example, as implemented by the safety-response triggering system 100 of
Returning to
If, in any iteration or time at step 204 (
Once the time delay initiated at the time delay step 208 (
In the exemplary implementation of
Returning to
In correspondence with the exemplary implementation of
Thus, the method 200 activates a safety response device (steps 212-216) when an acceleration impulse meets or exceeds a predetermined magnitude threshold (step 204) for at least an adjustable duration threshold (step 208).
While the foregoing description provides embodiments of the invention by way of example only, it is envisioned that other embodiments may perform similar functions and/or achieve similar results. Any and all such equivalent embodiments and examples are within the scope of the present invention and are intended to be covered by the appended claims.
| Number | Name | Date | Kind |
|---|---|---|---|
| 4243248 | Scholz | Jan 1981 | A |
| 4477732 | Mausner | Oct 1984 | A |
| 4984464 | Thomas | Jan 1991 | A |
| 5034891 | Blackburn | Jul 1991 | A |
| 5040118 | Diller | Aug 1991 | A |
| 5418722 | Cashler | May 1995 | A |
| 5483451 | Ohmae | Jan 1996 | A |
| 5521822 | Wang | May 1996 | A |
| 5732374 | Ohm | Mar 1998 | A |
| 6219606 | Wessels | Apr 2001 | B1 |
| 6299102 | Happ | Oct 2001 | B2 |
| 10040572 | Santana-Gallego | Aug 2018 | B2 |
| 10391960 | Settles | Aug 2019 | B2 |
| 10414501 | Thompson | Sep 2019 | B2 |
| 20180208141 | Mase | Jul 2018 | A1 |
| Number | Date | Country | |
|---|---|---|---|
| 20200384935 A1 | Dec 2020 | US |
