Harvesting energy from high-shock pulse events such as those experienced during high velocity impact and firing setback acceleration in munitions using piezoelectric-based harvesters and converting it to usable electrical energy is not new. However, efficient collection of the generated charges and its transfer to an electrical storage device such as a capacitor for pulse events with very short duration, such as those that last a small fraction of a millisecond such as 50–100 microseconds is challenging. Another challenge for such piezoelectric-based harvesters is their hardening to survive high levels of shock loading, sometimes in excess of 100–200,000 Gs. In this paper, the basic design and operation of two such piezoelectric-based energy harvesters and their charge collection and storage electronics are described. The novel methods described are shown to achieve this goal with very high efficiency. The paper also describes the development of test-beds to simulate electrical charge generation of the energy harvesting power sources during high velocity impact and munitions firing for use in the design and evaluation of the developed charge collection and storage electronics.

A new class of self-powered acceleration event detection sensors are presented that are powered by electrical energy harvested during munitions launch by integrated piezoelectric elements. The sensors are provided with a novel safety electronic and logic circuitry that is used to differentiate the firing event from all accidental events such as accidental drops, transportation vibration, and the like. When the launch conditions are detected from the magnitude of the experienced acceleration as well as its duration, the remaining electronics and logics circuitry of the device is enabled. The developed self-powered sensors may also be used in place of G-switches in munitions and other industrial and commercial devices with the advantage of activating not only from the magnitude of the experienced acceleration but also from its duration. The latter capability is essential in many munitions and commercial applications to avoid false switching event. For example in some cases dropping of around over a hard surface may impart higher peak acceleration than actual firing. And in many industrial and commercial devices and equipment, high-G and very short duration shock loadings do not cause damage and G-switches used to deactivate the device may not be desired to trip. Prototypes of the developed piezoelectric-based self-powered event detection sensors as standalone sensors and as switches for detecting and opening or closing circuitry upon detection of shock or vibration loading with prescribed magnitude and duration thresholds with integrated electronics and logics circuitry have been designed, fabricated and successfully tested for a number of munitions and industrial applications. In this paper the design and operation of such devices and their testing are described.

This paper deals with the geometric issues that arise in designing a system for measuring the orientation of an object in three dimensional space using a new class of wireless angular position sensors. The wireless sensors are waveguides that receive and record the electromagnetic energy emitted by a polarized RF source. The angular position of the waveguide relative to the source is indicated by the energy level. A system equipped with multiple waveguides is used as a 3D orientation sensor. This paper explores the geometry for orientation measurement using the system and provides the guidelines for sensor design.