Infrared Stereo Calibration for Unmanned Ground Vehicle Navigation

Many challenges still persist in the area of autonomous (and even semi-autonomous) vehicle navigation for unmanned ground vehicles (UGVs). One challenge is in detecting and classifying obstacles for avoidance and path planning. The use of laser-based sensors, such as lidar, has become quite common for assisting in such a task; however, lidar systems may be too expensive for certain applications, and are active, not passive sensors, so they may not be desirable in some missions. Lidar is adversely affected by smoke, dust, fog, and rain. Therefore, the use of passive camera sensors, such as typical color and infrared (IR) cameras, has become an important research topic in UGV navigation.

Posted in: Briefs, Defense, Sensors, Imaging, Optics, Sensors and actuators, Vibration

Damping Measurement for Wafer-Level Packaged MEMS Acceleration Sensors

Microelectromechanical system (MEMS) three-axis acceleration threshold sensors have been developed to measure acceleration threshold levels using voltage switching when the threshold is reached. Determining damping coefficients is important for categorizing how each threshold sensor or switch operates. Switches with different damping coefficients result in different mechanical impedances and response times. Analytical and numerical methods to model damping coefficient values based on empirical data are needed to characterize three-axis acceleration sensors; traditional methods use the displacement of an underdamped system to calculate the damping ratio.

Posted in: Briefs, Defense, MEMs, Sensors, Measuring Instruments, Sensors and actuators, Switches

Sensing Suspicious Powders Using Noncontact Optical Methods

Suspicious powder incidents continue to be a disruptive and costly problem. In-situ assessment of suspicious powders within inorganic matrices, particularly with powders of biological origin, is currently limited to detection by biochemical methodologies that react with monomers such as amino acids, nucleic acids, lipids, or macromolecule compounds comprised of these basic subunits. Current optical methods such as Raman spectroscopy using excitation in the near infrared at 785 nm or visible at 532 nm, have not been able to detect or distinguish biological materials from background or other materials.

Posted in: Briefs, Defense, Sensors, Instrumentation, Test & Measurement, Optics, Biohazards

Isotope Beta-Battery Approaches for Long-Lived Sensors

The energy density of isotopes exceeds that of chemical energy storage by six orders of magnitude. Isotopes are used in many commercial applications, and are produced and available at modest prices. The power requirements of many sensors and communications equipment can greatly reduce the power requirements of many devices such as sensors, light sources, and transmitters. Chemical batteries are the mainstay of power for these devices. However, chemical batteries have limited lifetimes. This makes remote use and replacement difficult for applications extending the lifetime use.

Posted in: Briefs, Defense, Power Management, Sensors, Batteries, Sensors and actuators

Selective, Sensitive, and Robust Electrochemical Detection of Anthrax

There exists an unmet need for rapid, sensitive, and field-stable assays for pathogen detection. Bacillus anthracis is the causative agent of anthrax poisoning. This Gram-positive bacterium secretes a tripartite toxin including a cell-binding protective antigen (PA), and the delivered toxins edema factor (EF) and lethal factor (LF). Anthrax poisoning has high mortality and, when delivered in the form of B. anthracis spores, has a very high environmental stability.

Posted in: Briefs, Defense, Sensors, Biohazards

New Devices Could Help Soldiers Detect Chemicals and Bio Threats

Researchers are refining for Army use a commercial technology that will allow soldiers to accurately and rapidly detect an array of chemical and biological hazards - from mustard agent to anthrax - and then transmit those results to their higher command. At the same time, the technology is smart enough to differentiate between those chemicals which are dangerous and those that a soldier has carried with him into the environment on his own skin, such as bug spray or hand sanitizer.

Posted in: Articles, Defense, Detectors

Integrated Underwater Security System

Winfrith Newburgh, Dorchester, UK
Bezons, France

Effective surveillance of coastal border areas requires the use of very sensitive and advanced radar systems and processing software. SIGNALIS and ATLAS ELEKTRONIK have jointly developed an interface for Cerberus Mod 2 Diver Detection Sonar (DDS), providing a fully integrated underwater surveillance and security system.

Posted in: Application Briefs, Aerospace, Defense, Electronics & Computers, Data Acquisition, Detectors, Sensors, Radar, Security systems, Marine vehicles and equipment

Data Acquisition Module

Diamond Systems Corp. (Mountain View, CA) has introduced DSMPE-DAQ0804, a rugged data acquisition PCIe MiniCard module. The DS-MPE-DAQ0804 offers eight 16-bit analog input channels, four 16-bit analog output channels, and 21 configurable digital I/O lines in a PCIe MiniCard form factor, with an extended operating temperature of -40 °C to +85 °C. The analog inputs provide single-ended and differential capability, 4 programmable input ranges, and 100 KHz aggregate sample rate. Features of the analog input circuitry include an integrated programmable timer to control A/D sample rates automatically.

Posted in: Products, Aerospace, Defense, Electronics & Computers, Data Acquisition

Digital Input Board

United Electronic Industries (UEI) (Walpole, MA) has released the DNx-DIO-449, 48 channel, digital input board. The board is compatible with all of UEI’s popular Cube, RACKtangle and FlatRACK chassis. Features include: Input range from 3.3 V to 150 V; monitors both AC and DC inputs; monitors contact closures without external components; fully programmable logic high/low levels and hysteresis; automatic change-of-state detection with 200 μS resolution time stamps; built-in A/D for analog voltage measurement of each input; internal signal injection for BIT (Built-In-self-Test).

Posted in: Products, Aerospace, Defense, Electronics & Computers, Data Acquisition, Software

Wireless Sensing — the Road to Future Digital Avionics

The performance of avionics systems is dictated by the timely availability and usage of critical health parameters. Various sensors acquire and communicate the desired parameters. In current scenarios, sensors are hardwired and the number of sensors are growing due to automation, which increases the accuracy of intended aircraft functions.

Posted in: Articles, Aerospace, Aviation, Defense, Sensors, Avionics, Flight control systems, Sensors and actuators