Active blast countermeasures
An explosion countermeasure system is provided including a first sensor device with a plurality of accelerometers configured to detect vertical acceleration of a vehicle; a countermeasure; a safe and arming device configured to impede activation of the countermeasure; and a processor in communication with the first sensor device and the safe and arming device. The processor may be configured to process acceleration signals received from the first sensor device and to make ready the safe and arming device and initiate the countermeasure based on results of processing the acceleration signals. Making ready the safe and arming device may be based on an initial acceleration exceeding a first threshold, and initiating the countermeasure may be based on the initial acceleration exceeding a second threshold and a velocity change exceeding a third threshold.
1. An explosion countermeasure system, comprising:
a first sensor device including a plurality of accelerometers configured to detect vertical acceleration of a vehicle; and
a processor in communication with said first sensor device, said processor configured to process acceleration signals received from said first sensor device and to initiate a countermeasure based on results of processing the acceleration signals;
wherein, said plurality of accelerometers are included in a sensor package and arranged to detect acceleration in the same direction,
the accelerometers in said sensor package share a sampling channel, with each of the accelerometers in said sensor package being assigned a different time slot, and
said processor is further configured with an integration module that integrates the acceleration signals to calculate a change in velocity, and initiating the countermeasure is based on (a) an initial acceleration exceeding a first threshold, and (b) a velocity change exceeding a second threshold.
2. The system of claim 1 , wherein said sensor package provides acceleration signals with a combined sampling rate of 6 kHz.
3. The system of claim 1 , comprising a plurality of said sensor packages.
4. The system of claim 1 , comprising at least five of said sensor packages.
5. The system of claim 1 , wherein initiating the countermeasure requires accelerations determined from at least two of said sensor packages to each exceed the first threshold.
6. The system of claim 1 , wherein the determination to initiate the countermeasure requires an acceleration determined from one of said sensor packages to exceed the first threshold, and an acceleration determined from another of said sensor packages to each exceed another acceleration threshold, the other acceleration threshold being different than the first threshold.
7. The system of claim 1 , wherein the processor is further configured to selectively initiate individual countermeasures in different areas of the vehicle based on signals received from different sensor packages associated with each of the different areas of the vehicle.
8. The system of claim 1 , wherein the first threshold is greater than 40 g.
9. The system of claim 1 , wherein the first threshold is in a range of 40 g to 60 g.
10. The system of claim 1 , wherein determining whether the second threshold is exceeded is based on a sum of values for a particular sensor package included in a buffer.
11. The system of claim 10 , wherein the sum of values is obtained from a 3 ms window in the buffer.
12. The system of claim 1 , wherein the processor is configured to initiate the countermeasure within 10 ms of the initial acceleration exceeding the first threshold.
13. The system of claim 1 , wherein the processor is further configured to make ready a safe and arming device based on the initial acceleration exceeding the first threshold, prior to making a determination to initiate the at least one countermeasure.
14. The system of claim 13 , wherein the processor is configured to make ready the safe and arming device and initiate the at least one countermeasure within 10 ms of the initial acceleration exceeding the first threshold.
15. The system of claim 13 , further comprising the safe and arming device.
16. The system of claim 1 , wherein the processor is further configured to selectively initiate individual countermeasures from among a plurality of countermeasures, to make ready safe and arming devices for all of the plurality of countermeasures based on the initial acceleration exceeding the first threshold, and to disarm at least one of the safe and arming devices based on buffered acceleration data for one or more of the sensor packages falling below the first threshold for a predetermined period of time.
17. The system of claim 1 , further comprising at least one countermeasure device, wherein the at least one countermeasure device includes one or more of a mass ejector and a thruster.
18. The system of claim 1 , wherein the processor is further configured to initiate an occupant protection device.
19. The system of claim 1 , wherein the processor is in further communication with a second sensor device that senses a different type of condition than the first sensor device, and the processor is further configured to process signals received from said second sensor device in determining whether to initiate the countermeasure.
20. An explosion countermeasure system, comprising:
a first sensor device including a plurality of accelerometers configured to detect vertical acceleration of a vehicle;
a countermeasure;
a safe and arming device configured to impede activation of said countermeasure;
a processor in communication with said first sensor device and said safe and arming device, said processor configured to process acceleration signals received from said first sensor device and to make ready the safe and arming device and initiate the countermeasure based on results of processing the acceleration signals;
wherein, making ready the safe and arming device is based on an initial acceleration exceeding a first threshold,
initiating the countermeasure is based on the initial acceleration exceeding a second threshold, and a velocity change exceeding a third threshold, and
the velocity change is calculated based at least in part on integrating a plurality of acceleration readings.
21. The system of claim 20 , wherein the first and second thresholds are substantially equal.
22. The system of claim 20 , wherein the first threshold is greater than 30 g.
23. The system of claim 20 , wherein determining whether the third threshold is exceeded is based on a sum of values for a particular sensor included in a buffer.
24. The system of claim 20 , wherein the processor is configured to make ready the safe and arming device and initiate the countermeasure within 10 ms of the initial acceleration exceeding at least one of the first threshold and the second threshold.
25. An explosion detection system comprising:
a communication bus in communication with a plurality of sampling channels, each sampling channel including multiplexed acceleration signals from a plurality of sensors included within a sensor package; and
a processor configured to
process the multiplexed acceleration signals from the plurality of sampling channels,
determine the occurrence of an explosion based on the acceleration signals, and
initiate an explosion countermeasure based on the determination that an explosion has occurred,
wherein processing the multiplexed acceleration signals includes determining an acceleration value for the sensor package based on the acceleration signals from at least two of the plurality of sensors included within the sensor package, and
an effective sampling rate for the sensor package is greater than a sampling rate of each of the plurality of sensors included within the sensor package.
26. The system of claim 25 , wherein, the effective sampling rate is 6 kHz.
27. The system of claim 25 , wherein the processor is configured to determine the occurrence of the explosion and initiate the explosion countermeasure within 10 ms of registering an initial acceleration exceeding a first threshold.
28. The system of claim 27 , wherein the processor is further configured to initiate charging of a safe and arming device based on the initial acceleration exceeding the first threshold, prior to making a determination to initiate the explosion countermeasure.