TECHNOLOGY AREA(S): Nuclear Technology OBJECTIVE: Demonstrate a test bed that smoothly and accurately follows a defined acceleration and velocity profile in the forward direction, decelerates to a defined stop point, and reverses direction to return to the original start position. DESCRIPTION: Next-generation weapons include very accurate navigation systems. The 10-mile long Holloman High Speed Test Track (HHSTT) is aligned within 0.040 inches of a precisely surveyed fiducial reference curve. The 30,000 feet of the HHSTT includes an array of precisely surveyed optical interrupter blades whose leading and trailing edges are measured to within a 0.004 inches accuracy. When the sled system is in motion, the data collection timing system time tags the interrupted beam's position accurately within 10 nanoseconds (ns). This precise and accurate reference truth is essential to determining the error sources of individual inertial sensor errors. Multiple forward and reverse accelerations and velocities allow separation and quantification of sensor errors that are highly correlated if only short-duration, unidirectional accelerations are used. The current state-of-the-art in guidance systems testing on rocket sleds is to 1) use a set of rockets to launch the sled in the down track/forward direction, decelerate it with water braking and then tow it back to the start point, or 2) use a rocket sled with opposing rocket motors wherein the first set creates forward direction acceleration and the second set fires at the correct position to decelerate the sled and then reverse the motion to produce reverse accelerations and velocities. There are numerous disadvantages to these rocket sled test approaches. First, rocket sled tests are expensive given all the safety issues and rocket motor costs. In the first test method, the forward acceleration and velocity adequately resembles a launch condition while water braking does generate deceleration to separate sensor errors. However, the duration of the test is very short and produces only limited data from which to characterize the inertial sensor errors. The second method is subject to reliability issues given that both sets of motors must fire at the correct time to create the defined profile. This method also suffers from an inability to adequately determine the reversal time-position and define the final time and position of the reverse leg of the cycle. Both methods require the sleds to be removed from the test track to replace the propulsion systems which further degrades the time-position reference truth. The successful outcome of this topic will provide a test bed that shall:1) Smoothly accelerate a payload at variable g's from 0.5g up to 2.5 g's (thr)/8 g's (obj) from stationary to 165 km/h (thr)/400 km/h (obj), sustain velocity up to 100 s and smoothly decelerate at the inverse variable g-range to stationary.2) Accurately repeat the forward and reverse profile up to 20 times in a single test.3) Minimize angular and translational vibrations for frequencies less than 60 Hz.4) Operate on the HHSTT without interference with other tests.5) House an instrumented rack (200kg, 1m x 1m x 1.3m) and accompanying Advanced Digital Antenna Program (ADAP) Controlled Reception Pattern Antenna (CRPA) and Locata system antenna.6) Provide environmental protection from rain/humidity/dust/etc.7) Provide environmental control in the form of cooling. PHASE I: Research technologies and new applications of them to produce the required profiles while meeting the other requirements. Assemble an analysis of alternatives to rank possible solutions with respect to technical, cost and schedule risk. Develop a conceptual design of at least one solution worthy of Phase II prototype demonstration. PHASE II: Design, build and demonstrate some of the system critical technologies on the HHSTT. PHASE III DUAL USE APPLICATIONS: Military Application: Test items that require a highly accurate reference.Commercial Application: Energy storage device, propulsion system, regenerative braking system, strong lightweight materials developed & intelligent control systems could be used to improve passenger and freight rail service. REFERENCES: RVTV Cans and Cannots, Norm Ingold, 24 Feb 2015 (Available on request). Ingold, N. L., "Reverse Velocity Rocket Sled Test Bed for Inertial Guidance Systems, 38th Annual Meeting of the Institute of Navigation, Colorado Spring, Colorado, 15-17 June 1982, (Available on request) Ingold, N. L., "Proposed Use of Retro Rockets for Optimizing Analysis of Inertial Guidance System Errors in 100-G Sled Tests, Central Inertial Guidance Test Facility, 6585th Test Group (AFSC), Holloman Air Force Base, NM, circa 1980, (Available on request). KEYWORDS: composite materials, regenerative braking, energy storage, propulsion system, propulsion assist
