Browse Topic: Quality, Reliability, and Durability
ABSTRACT This work investigates the effects of obstacle uncertainty on the speed, distance, and feasibility of a planned traversal path. Simulation results for artificial and real-world environments are used to numerically quantify how geometric uncertainty within a map affects path traversal cost. A significant outcome of this research is the discovery of a relationship between increasing uncertainty and path cost. As obstacle uncertainty increases, previously planned routes can become infeasible as they effectively become blocked off due to uncertainty in the obstacle geometry. This paper illustrates a method that can serve to increase the speed, simplicity, and reliability of path planning, while allowing uncertainty to be included in the mobility analysis. Citation: S. Tau, S. Brennan, K. Reichard, J. Pentzer, D. Gorsich, “The Effects of Obstacle Dimensional Uncertainty on Path Planning in Cluttered Environments”, In Proceedings of the Ground Vehicle Systems Engineering and
ABSTRACT Program offices and the test community all desire to be more efficient with respect to testing but currently lack the analytical tools to help them fit early subsystem level testing into a framework which allows them to perform assessments at the system level. TARDEC initiated a Small Business Innovative Research (SBIR) effort to develop and deploy a system reliability testing and optimization tool that will quantify the value of subsystem level tests in an overall test program and incorporate the results into system level evaluations. The concept software, named the Army Lifecycle Test Optimization (ALTO) tool, provides not only the optimization capability desired, but also other key features to quickly see the current status, metrics, schedule, and reliability plots for the current test plan. As the user makes changes to the test plan, either by running the optimization or adjusting inputs or factors, the impacts on each of these areas is computed and displayed
ABSTRACT This paper describes an approach to aid the many military unmanned ground vehicles which are still teleoperated using a wireless Operator Control Unit (OCU). Our approach provides reliable control over long-distance, highly-latent, low-bandwidth communication links. The innovation in our approach allows refinement of the vehicle’s planned trajectory at any point in time along the path. Our approach uses hand-gestures to provide intuitive fast path editing options, avoiding traditional keyboard/mouse inputs which can be cumbersome for this application. Our local reactive planner is used for vehicle safeguarding. Using this approach, we have performed successful teleoperation nearly 1500 miles away over a cellular-based communications channel. We also discuss results from our user-tests which have evaluated our innovative controller approach with more traditional teleoperation over highly-latent communication links
ABSTRACT Variable displacement pumps have been used in automotive transmissions for decades. L3T had high confidence that a Variable Displacement Oil (VDO) pump would increase overall transmission efficiency. An off-the-shelf (OTS) or OTS modified pump in this pressure and flow range was not found. Therefore, a VDO pump is being developed with the known risk of replacing a highly reliable pump with a new better performing pump of unknown reliability. In this document the development of this VDO pump is discussed. Initial testing of the VDO pump demonstrated an average 25HP savings in pumping losses throughout the transmission operating ranges. At this point, durability testing has not been performed
ABSTRACT Durability analysis as applied to high mobility off-road ground vehicles involves simulating the vehicle on rough terrains and cascading the loads throughout the structure to support the verification of various components. For components within the hull structure, the rigid body accelerations of the hull are transformed to the component location producing a prescribed g-load time history. This modeling method works extremely well for items which are bolted in place but is inappropriate for stowage systems such as boxes and shelves where cargo can experience intermittent contact and impacts. One solution is to create a dynamic contact nonlinear finite element model of the stowage solution with supported cargo and subject them to the same acceleration profile. This approach effectively resolves the stresses needed to perform fatigue evaluations but is a computationally and labor intensive process. The resources required for single design point verification cannot be justified
ABSTRACT Leveraging an open standard may still not achieve the desired interoperability between systems. Addressing “lessons learned” from past implementations of open standards for various Department of Defense (DoD) acquisition programs is critical for future success. This paper discusses past issues which range from insufficient technical detail, when and how to apply a given specification, verification of an implementation’s compliance, to inconsistent and imprecise contractual language. This paper illustrates how the Vehicular Integration for C4ISR/EW Interoperability (VICTORY) initiative addresses these challenges to enable interoperability on Army ground vehicles, as well as facilitate rapid technology insertion and incorporation of new capabilities. VICTORY represents a leap ahead in solving interoperability challenges and defining open standards
ABSTRACT Problem: The traditional four (4) methods for improving reliability; 1) High design safety margin, 2) Reduction in component count or system architectural complexity, 3) Redundancy, and 4) Back-up capability, are often ignored or perceived as being excessively costly in weight, space claim as well as money. Solution 1: Discussed here are the practical and very cost effective methods for achieving improved reliability by Functional Interface Stress Hardening (FISHtm or FISHingtm). The Author has been able to apply FISH to eliminate 70-92% of unscheduled equipment downtime, within 30-60 days, for more than 30 of the Fortune 500 and many other large companies which utilize automation controls, computers, power electronics and hydraulic control systems. Solution 2: From Structured Innovation the 33 DFR Methods & R-TRIZ Tool can be used to grow or improve reliability, via rapid innovation. The R-TRIZ tool) is provided so that users can instantly select the best 2, 3 or 4 of these
ABSTRACT Reliability Physics simulations for electronic assemblies has matured to become best practice during specification and design. However, the potential advantages of these simulations to programs and integrators are more far reaching. This paper will explore how the simulations can be used for virtual qualification, reliability assurance, maintenance scheduling and obsolescence management. Citation: Ed Dodd, “Reliability Simulations for Electronic Assemblies: Virtual Qualification, Reliability Assurance, Maintenance Scheduling and Obsolescence Mitigation”, In Proceedings of the Ground Vehicle Systems Engineering and Technology Symposium (GVSETS), NDIA, Novi, MI, Aug. 13-15, 2019
ABSTRACT Significant Design for Reliability (DfR) methodology challenges are created with the integration of autonomous vehicle technologies via applique systems in a ground military vehicle domain. Voice of the customer data indicates current passenger vehicle usage cycles are typically 5% or less (approximately 72 minutes of use in a twenty-four hour period) [2]. The time during which vehicles currently lay dormant due to drivers being otherwise occupied could change with autonomous vehicles. Within the context of the fully mature autonomous military vehicle environment, the daily vehicle usage rate could grow to 95% or more. Due to this potential increase in the duty or usage cycle of an autonomous military vehicle by an order of magnitude, several issues which impact reliability are worth exploring. Citation: M. Majcher, J. Wasiloff, “New Design for Reliability (DfR) Needs and Strategies for Emerging Autonomous Ground Vehicles”, In Proceedings of the Ground Vehicle Systems
ABSTRACT The current reliability growth planning model used by the US Army, the Planning Model for Projection Methodology (PM2), is insufficient for the needs of the Army. This paper will detail the limitations of PM2 that cause Army programs to develop reliability growth plans that incorporate unrealistic assumptions and often demand that infeasible levels of reliability be achieved. In addition to this, another reliability growth planning model being developed to address some of these limitations, the Bayesian Continuous Planning Model (BCPM), will be discussed along with its own limitations. This paper will also cover a third reliability growth planning model that is being developed which incorporates the advantageous features of PM2 and BCPM but replaces the unrealistic assumptions with more realistic and customizable ones. The internal workings of this new TARDEC developed simulation-based model will be delved into with a focus on the advantages this model holds over PM2 and BCPM
ABSTRACT Silicon carbide (SiC) semiconductor devices offer several advantages to power converter design when compared with silicon (Si). An increase in power density can be achieved with SiC thanks to the reduced conduction and switching losses and to the ability to withstand higher temperatures [1]. The main system level benefits of using SiC devices on mobile hybrid power systems include large reductions in the size, weight, and cooling of the power conditioning. In this paper, the authors describe the Wide-bandgap-enabled Advanced Versatile Energy System (WAVES) with a focus on the design and testing of a SiC prototype of a WAVES power inverter. The prototype is a 10 kW three-phase AC/DC inverter that is air-cooled, IP-67 rated, bi-directional, operates down to a power factor of 0.4, and designed to have overload capability up to 350% for up to 250µs of nominal rating. Because the inverter is bidirectional, it may be used as an AC input to DC output battery charger or as a DC input
ABSTRACT Of the tests of any good theory or suppositional work, the most critical is whether it can forecast the need or accurately describe the number, timing, event and impact of the endeavor. In order to reduce the risk and to exponentially increase the rate of success a continual reevaluation of the data and reconfiguration of the plan will be required, must be properly front-loaded with the appropriate human capital. This is precisely where the application of Six Sigma, Project Management and, Six Sigma for Human Capital works’ intimately with Risk Management to mitigate error and insure the ultimate success of the effort. This is critical in business, critical in the field for greater energy efficiency for soldiers. Unified in concert as core disciplines, the identification of human capital for specialists required at any particular point in the project especially in the definition and design phases, is determined with greater accuracy. Critically predictable and integrated into
ABSTRACT The demand for mobile, secure communications has been and will continue to be a fundamental requirement for dismounted, urban and distributed operations in the field. It is imperative that soldiers on the front lines receive actionable information in a timely, secured and uninterrupted manner to increase force protection and effectiveness. In this paper, we describe a novel, high technical maturity (TRL 8+) communications link that offers the mounted and dismounted soldier secure, beyond line of sight, encrypted capability for weapons control and command & control of multiple platforms. An innovative spread spectrum waveform was designed from the ground up to deliver necessary functionality for reliable communications amongst multiple nodes with a data rate and range commensurate with battlefield scenarios
ABSTRACT The Integrated Systems Engineering Framework (ISEF) is an Army Research, Development, and Engineering Command (RDECOM) solution to address stovepiped systems engineering(SE) information and processes, disparate tools united by custom, one-off integrations, and a lack of accepted, common standards that exists in today’s Department of Defense (DoD) operating environment. Ever increasing technical complexity of fielded solutions combined with budgetary constraints push DoD engineers to “do more with less,” requiring a technical management solution that allows them collaborate virtually yet effectively with distributed engineers and other stakeholders. Easy access to systems engineering tools and information through a single “cloud” based application allows connections between federated databases, and facilitates knowledge preservation over time to avoid “reinventing the wheel” when new programs replace retired ones. ISEF is an ever-expanding collection of systems engineering
ABSTRACT This paper discusses various soft security considerations that should be accounted for in the next generation of advanced military unmanned systems. By modeling unmanned system teams as mobile ad hoc networks, we underscore the different types of information-based security vulnerabilities that motivated adversaries may be able to exploit in unmanned systems. Then we provide an overview of computational trust and show that it can be used to defend against these vulnerabilities by finding the most reliable agents to interact with from a pool of potential agents. Finally, we discuss ongoing work at U.S. Army TARDEC that is applying computational trust within a vehicle controller for autonomous convoy operations
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