This paper describes Applied Research Associates’ (ARA) recent advances in Soldier augmented reality (AR) technology. Our AR technology, called ARC4, delivers heads-up situational awareness to the dismounted warfighter, enabling non-line-of-sight team coordination in distributed operations. ARC4 combines compact head tracking sensors with advanced pose estimation algorithms, network management software, and an intuitive AR visualization interface to overlay tactical iconic information accurately on the user’s real-world view. The technology supports heads-up navigation, blue-force tracking, target handoff, image sharing, and tagging of features in the environment. It integrates seamlessly with established network protocols (e.g., Cursor-on-Target) and Command and Control software tools (e.g., Nett Warrior, Android Tactical Assault Kit) and interfaces with a wide range of daytime see-through displays and night vision goggles to deliver real-time actionable intelligence, day or night. We describe our pose estimation framework, which fuses inertial data, magnetometer data, GPS, DTED, and digital imagery to provide measurements of the operator’s precise orientation. These measurements leverage mountainous terrain horizon geometry, known landmarks, and sun position, enabling ARC4 to achieve significant improvements in accuracy compared to conventional INS/GPS solutions of similar size, weight, and power. We detail current research and development efforts toward helmet-based and handheld AR systems for operational use cases and describe extensions to immersive training applications.
In addition to military radios, modern warfighters carry cell phones, GPS devices, computers, and night-vision aids, all
of which require electrical cables and connectors for data and power transmission. Currently each electrical device
operates via independent cables using conventional cable and connector technology. Conventional cables are stiff and
difficult to integrate into a soldier-worn garment. Conventional connectors are tall and heavy, as they were designed to
ensure secure connections to bulkhead-type panels, and being tall, represent significant snag-hazards in soldier-worn
applications. Physical Optics Corporation has designed a new, lightweight and low-profile electrical connector that is
more suitable for body-worn applications and operates much like a standard garment snap. When these connectors are
mated, the combined height is <0.3 in. - a significant reduction from the 2.5 in. average height of conventional
connectors. Electrical connections can be made with one hand (gloved or bare) and blindly (without looking).
Furthermore, POC's connectors are integrated into systems that distribute data or power from a central location on the
soldier's vest, reducing the length and weight of the cables necessary to interconnect various mission-critical electronic
systems. The result is a lightweight power/data distribution system offering significant advantages over conventional
electrical connectors in soldier-worn applications.
In this paper, a novel concept of energy harvesting, applicable to both wired and wireless self-powered low-power
electronic devices, is discussed. Types of energy harvesting include solar/optical, thermal, IR, and mechanical. Overall
power budgets and control circuitry are discussed, including maximizing Mean Time between Battery
Replacement/Recharge values. It is shown that in the case of low-power wireless electronics, surprisingly low amounts
of daily direct solar exposure are sufficient to satisfy overall system power consumption.
System-on-chip (SoC) single-die electronic integrated circuit (IC) integration has recently been attracting a great
deal of attention, due to its high modularity, universality, and relatively low fabrication cost. The SoC also has low
power consumption and it is naturally suited to being a base for integration of embedded sensors. Such sensors can
run unattended, and can be either commercial off-the-shelf (COTS) electronic, COTS microelectromechanical
systems (MEMS), or optical-COTS or produced in house (i.e., at Physical Optics Corporation, POC). In the
version with the simplest electronic packaging, they can be integrated with low-power wireless RF that can
communicate with a central processing unit (CPU) integrated in-house and installed on the specific platform of
interest. Such a platform can be a human body (for e-clothing), unmanned aerial vehicle (UAV), unmanned ground
vehicle (UGV), or many others. In this paper we discuss SoC-centric embedded unattended sensors in Homeland
Security and military applications, including specific application scenarios (or CONOPS). In one specific example,
we analyze an embedded polarization optical sensor produced in house, including generalized Lambertian light-emitting
diode (LED) sources and secondary nonimaging optics (NIO).
Battery power resource management becomes a critical issue in the case of self-powered remote wireless RF electronics,
where the basic parameter is time of system operation before battery recharging or battery replacement. In such cases,
very often related to physical protection against antitampering (AT), proper theoretical modeling of a battery driven
power supply in the context of a given digital electronic system is of utmost importance. Such modeling should include
various types of batteries (primary and secondary), various self-discharge processes in different temperatures, and even
energy harvesting, the latter to supply power for long-term content, low-power electronic subsystems. In this paper we
analyze simple modeling of resource power management, including variations of all of these parameters and
Binary sensor systems are various types of analog sensors (optical, MEMS, X-ray, gamma-ray, acoustic, electronic, etc.),
based on the binary decision process. Typical examples of such "binary sensors" are X-ray luggage inspection systems,
product quality control systems, automatic target recognition systems, numerous medical diagnostic systems, and many
others. In all these systems, the binary decision process provides only two mutually exclusive responses: "signal" and
"noise." There are also two types of key parameters that characterize either system (such as false positive and false
negative), or a priori external-to-system conditions (such as absolute probabilities). In this paper, by using a strong
medical analogy, we analyze a third type of key parameter that combines both system-like and a priori information, in
the form of so called Bayesian Figures of Merit, and we show that the latter parameter, in the best way, characterizes a
binary sensor system.
This paper discusses Physical Optics Corporation's (POC) wearable snap connector technology that provides for the
transfer of data and power throughout an electronic garment (e-garment). These connectors resemble a standard garment
button and can be mated blindly with only one hand. Fully compatible with military clothing, their application allows
for the networking of multiple electronic devices and an intuitive method for adding/removing existing components from
the system. The attached flexible cabling also permits the rugged snap connectors to be fed throughout the standard
webbing found in military garments permitting placement in any location within the uniform. Variations of the snap
electronics/geometry allow for integration with USB 2.0 devices, RF antennas, and are capable of transferring high
bandwidth data streams such as the 221 Mbps required for VGA video. With the trend towards providing military
officers with numerous electronic devices (i.e., heads up displays (HMD), GPS receiver, PDA, etc), POC's snap
connector technology will greatly improve cable management resulting in a less cumbersome uniform. In addition, with
electronic garments gaining widespread adoption in the commercial marketplace, POC's technology is finding
applications in such areas as sporting good manufacturers and video game technology.
Mechanical testing of a bulk, single-crystal sample of Ni<sub>50</sub>Mn<sub>29</sub>Ga<sub>21</sub> produced large hysteresis loops indicating the potential for the material to be used as a damper. Damping capacity was measured as a function of energy absorbed by the material relative to the mechanical energy input to the system. Tan delta, the tangent of the phase lag between stress and strain, was calculated and shown to increase as a function of maximum strain level. Five strain levels were evaluated (1%, 2%, 3%, 3.5%, and 3.7%) with tan delta values increasing from 0.6 at 1% strain level to 1.1 at 3.7% strain level. The secant modulus of these curves was also evaluated at each strain level to characterize the sample in terms of both damping and stiffness. The maximum secant modulus of 285 MPa occurred at the 1% strain level and decreased to 56 MPa at 3.7% strain. Examining the stress and strain values in the time domain reveals a varying time lag and thus the reported values for tan d are considered an average measure of the material's damping capacity.
Polycrystalline Ni-Mn-Ga in bulk, pulsed laser deposition (PLD) thin film, and radio frequency (RF) sputtered thin film are studied. A thin film of direct current (DC) magnetron sputter deposited NiTi was also used in the study. A polycrystalline Ni-Mn-Ga bulk sample was measured to have a tan δ = 0.4925 and a maximum elastic modulus E = 7.3 GPa. Material characterization studies were performed on polycrystalline Ni-Mn-Ga thin films deposited by PLD onto single crystal (100) Si and (100) MgO substrates at substrate temperatures ranging from 550°C to 650°C. Damping measurements on RF sputter deposition of 1 μm Ni-Mn-Ga and 10 μm of NiTi both on copper substrates were performed in cantilever beam ring down tests. Results show 1 μm RF sputter deposited Ni-Mn-Ga thin film on a 54 μm copper substrate improves damping properties.