Electronic setback detection method for 40 mm munitions
In a projectile launch environment, a fuzing safety device independently generates its own voltage upon setback which then is then used to arm the projectile. The arming is done independently of any on board battery rise time, and setback scenarios are detected free of false impacts such as dropping or jostling. The fuzing safety device includes a piezoelectric sensor for detecting motion in the projectile.
1. In a projectile launch environment, a fuzing safety device configured to generate a first voltage signal ( 425 ) upon setback during a projectile launch, without any voltage from an onboard battery device, the fuzing safety device comprising:
a projectile;
a piezoelectric sensor chip ( 302 );
a mass ( 301 ) configured to strike the piezoelectric sensor chip ( 302 ) to generate the first voltage signal ( 425 );
wherein the first voltage signal ( 425 ) is further configured to arm the projectile upon the projectile launch.
2. The fuzing safety device of claim 1 , wherein the device is configured to ascertain and discard voltage signals generated by action of non-setback stimulus forces or voltage signals not generated by the piezoelectric sensor chip ( 302 ).
3. The fuzing safety device of claim 2 wherein the first voltage signal ( 425 ) is configured to arm the projectile through projectile components which comprise a voltage clipper, a filter, a rectifier, an energy storage, and an environmental detection circuit which enables an electronic safe and arm device to arm the projectile.
4. The fuzing safety device of claim 3 wherein the voltage clipper limits peaks in any waveform in the first voltage signal ( 425 ).
5. The fuzing safety device of claim 4 wherein the filter eliminates high frequencies from waveforms in the first voltage signal ( 425 ).
6. The fuzing safety device of claim 4 wherein the voltage clipper comprises a resistor in series with a pair of opposing zener diodes.
7. The fuzing safety device of claim 5 wherein waveforms in the first voltage signal ( 425 ) are limited to all be only of the same polarity.
8. The fuzing safety device of claim 5 wherein the filter comprises a low pass filter which includes a resistor and a capacitor in series.
9. The fuzing safety device of claim 7 wherein voltage outputs from the rectifier are accumulated in the energy storage.
10. The fuzing safety device of claim 7 wherein the rectifier comprises a grounded quadruple diode bridge circuit.
11. The fuzing safety device of claim 9 wherein the environmental detection circuit enables the electronic safe and arm device to arm the projectile only when levels in the energy storage are at a predetermined value.
12. The fuzing safety device of claim 9 wherein the energy storage comprises a resistor in parallel with a capacitor.
13. The fuzing safety device of claim 11 wherein the environmental detection circuit comprises a comparator.
14. In a projectile launch environment, a fuzing safety device configured to generate a voltage signal upon setback during a projectile launch, without any voltage from an onboard battery device, the fuzing safety device comprising:
a projectile;
a piezoelectric coin sensor ( 202 );
a mass ( 201 ) configured to strike the piezoelectric coin sensor ( 202 ) to generate said voltage signal;
wherein said voltage signal is further configured to arm the projectile upon the projectile launch.
15. The fuzing safety device of claim 14 , wherein the device is configured to ascertain and discard voltage signals generated by action of non-setback stimulus forces or voltage signals not generated by the piezoelectric coin means ( 202 ).