With the large number of Improvised Explosive Devices (IEDs) and Unexploded Ordnance (UXO) being encountered during recent military operations, there exists a need for Explosive Ordnance Disposal (EOD) mobile robots. These robots are predominately used for surveillance and neutralization of these explosive threats from a safe distance. The nature of the mission means that these vehicles are prone to being damaged or destroyed. Current commercially available systems, although capable of performing the mission, are costly and in too short of supply to be lost or damaged in large numbers. At last year's SPIE conference the NAVEODTECHDIV proposed an alternative: a low cost, mobile robot which used commercial off-the-shelf (COTS) parts and was tailored to the types of missions that
EOD soldiers commonly perform. The prototype of this low-cost robot, the RAMBOT (Readily Available Maintainable Robot), has been continuously improved over the past year. There have been significant improvements to the original design in the areas of communication, manipulation, and electronics. The result of this work is a final prototype design, which is currently undergoing extensive testing to characterize its capabilities. Some of these tests include vehicle characteristics such as vehicle speed and mobility, vehicle weight and size, as well as maximum effective communication range, susceptibility to temperature, manipulator load limitations, and battery longevity. This conference paper will present the design changes to the robot and fully report on the results from the test series conducted thus far.
The continuing military operations in Iraq and Afghanistan have resulted in a rapidly growing demand for mobile robots to be used during Explosive Ordnance Disposal operations. These robots are predominately used by EOD technicians for surveillance and neutralization of explosive threats from a safe standoff distance. The hazardous nature of the mission these vehicles help perform requires them to be expendable. Current commercially available systems, however, although capable of performing the mission, are costly and are not currently available in the large quantities needed by EOD technicians. The Naval EOD Technology Division (NAVEODTECHDIV) proposes an alternative; a low cost, mobile robot using Commercial Off-The-Shelf (COTS) parts that is specifically tailored to perform hazardous EOD missions. The main functions of this robot are efficient surveillance and explosive threat neutralization. The use of COTS parts allows for streamlined field supportability and repair. A proposed speed of five miles per hour is a drastic improvement over many existing EOD robots and will allow EOD teams to quickly survey and assess potentially dangerous situations. The manipulator will be capable of precision placement of neutralization charges. The cost of this proposed robot is $10,000. Current commercial robots capable of performing these EOD tasks range in price from $40,000 to over $150,000. This conference paper will describe the robot design and prototyping process, from gathering requirements to fabrication and testing.
Modulating retro-reflectors (MRR) couple passive optical retro-reflectors with electro-optic modulators to allow free-space optical communication with a laser and pointing/acquisition/tracking system required on only one end of the link. In operation a conventional free space optical communications terminal, the interrogator, is used on one end of the link to illuminate the MRR on the other end of the link with a cw beam. The MRR imposes a modulation on the interrogating beam and passively retro-reflects it back to the interrogator. These types of systems are attractive for a asymmetric communication links for which one end of the link cannot afford the weight, power or expense of a conventional free-space optical communication terminal. Recently, MRR using multiple quantum well (MQW) modulators have been demonstrated using a large area MQW placed in front of the aperture of a corner-cube. For the MQW MRR, the maximum modulation can range into the gigahertz, limited only by the RC time constant of the device. This limitation, however, is a serious one. The optical aperture of an MRR cannot be too small or the amount of light retro-reflected will be insufficient to close the link. For typical corner-cube MQW MRR devices the modulator has a diameter between 0.5-1 cm and maximum modulation rates less than 10 Mbps. In this paper we describe a new kind of MQW MRR that uses a cat’s eye retro-reflector with the MQW in the focal plane of the cat’s eye. This system decouples the size of the modulator from the size of the optical aperture and allows much higher data rates. A 10 Mbps free space link over a range of 1 km is demonstrated. In addition a laboratory of a 70 Mbps MQW focal plane is described.
We present an optical turbulence model that has evolved from the PAMELA model. After a preliminary report in SPIE 2003 it became apparent that more data was needed to refine this adaptive model. This led us to take twelve months of over-land data (~100 meters pathlength) at the Chesapeake Bay Detachment of the Naval Research Lab. We present data throughout the year with varying environments with comparison with the model prediction. Our recent modification includes segmenting the windspeed to 3 sections, morning, afternoon, and night for better fitting. This is an attempt to incorporate variable wind speed into the model which is known to contribute significantly to the turbulence in the atmosphere. In addition, we present preliminary results from the over-the-bay data (10 km pathlength).
We describe the development of a portable NRL seeing monitor which consists of a 12 inch Meade f/10 telescope with a Dalsa Cad6 260x260 camera having 10 micron pixels. This seeing monitor is capable of up to 700 frames per second. We have three different techniques to measure Fried's r0 parameter: full aperture, two-hole mask, and two-hole mask with in-line intensifier. For the observations done at the Anderson Mesa, Arizona site in January-July 2004, we present comparison of Fried's r0 obtained. Calibration, observing techniques, and data analysis techniques are described. Comparison of the three different techniques is discussed.