Browse Topic: Reliability
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 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
ABSTRACT Leader-follower autonomous vehicle systems have a vast range of applications which can increase efficiency, reliability, and safety by only requiring one manned-vehicle to lead a fleet of unmanned followers. The proper estimation and duplication of a manned-vehicle’s path is a critical component of the ongoing development of convoying systems. Auburn University’s GAVLAB has developed a UWB-ranging based leader-follower GNC system which does not require an external GPS reference or communication between the vehicles in the convoy. Experimental results have shown path-duplication accuracy between 1-5 meters for following distances of 10 to 50 meters. Citation: K. Thompson, B. Jones, S. Martin, and D. Bevly, “GPS-Independent Autonomous Vehicle Convoying with UWB Ranging and Vehicle Models,” In Proceedings of the Ground Vehicle Systems Engineering and Technology Symposium (GVSETS), NDIA, Novi, MI, Aug. 16-18, 2022
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 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 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 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 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 The M1 Abrams will be the primary heavy combat vehicle for the US military for years to come. Improvements to the M1 that increase reliability and reduce maintenance will have a multi-year payback. The M1 engine intake plenum seal couples the air intake plenum to the turbine inlet, and has opportunities for improvement to reduce leakage and intake of FOD (foreign object debris) into the engine, which causes damage and premature wear of expensive components
ABSTRACT This paper addresses some aspects of an on-going multiyear research project of GP Technologies for US Army TARDEC. The focus of the research project has been the enhancement of the overall vehicle reliability prediction process. This paper describes briefly few selected aspects of the new integrated reliability prediction approach. The integrated approach uses both computational mechanics predictions and experimental test databases for assessing vehicle system reliability. The integrated reliability prediction approach incorporates the following computational steps: i) simulation of stochastic operational environment, ii) vehicle multi-body dynamics analysis, iii) stress prediction in subsystems and components, iv) stochastic progressive damage analysis, and v) component life prediction, including the effects of maintenance and, finally, iv) reliability prediction at component and system level. To solve efficiently and accurately the challenges coming from large-size
ABSTRACT A toolchain must be functionally cohesive with a business process, especially in technical domains such as complex systems engineering. Despite the industry-wide shift towards model-based digitization within engineering organizations, there is a lack of development in implementing model-based RAMS (Reliability, Availability, Maintenance, Safety) processes. This results in a missed opportunity to create value throughout the entire system lifecycle, from conceptual design to operations. This paper proposes some reasons for this and outlines a framework for evaluating model-based toolchains in the context of the entire Engineering cycle. A model-based architecture for RAMS is proposed and contrastively evaluated with respect to SysML. Key use cases are identified, and benefits are demonstrated using Maintenance Aware Design Environment Software. Citation: J. Langton, S. Hilton, “Iterative Co-Design Of Organizational Processes and Toolchains For Model-Based Reliability
ABSTRACT The concept of Autonomous Vehicles ultimately generating an “order of magnitude” potential increase in the duty or usage cycle of a vehicle needs to be addressed in terms of impact on the reliability domain. Voice of the customer data indicates current passenger vehicle usage cycles are typically very low, 5% or less. Meaning, out of a 24 hour day, perhaps the average vehicle is actually driven only 70 minutes or less. Therefore, approximately 95% of the day, the vehicles lay dormant in an unused state. Within the context of future fully mature Autonomous Vehicle environment involving structured car sharing, the daily vehicle usage rate could grow to 95% or more
ABSTRACT Value Engineering (VE) is an organized effort directed at analyzing the function of a product, service, or process to achieve the lowest total cost of effective ownership while meeting the customer’s needs. A comparison as to how VE is applied and to what extent is made between the automotive industry and the Government using the Program Executive Office Ground Combat Systems (PEO GCS) as a standard. Both the automotive industry and the Government use common VE techniques to conduct VE studies. Both use VE to manage functionality to yield value to the customer. Neither the Government nor the automotive industry sacrifices the quality of the product or its reliability in the name of cost. Both the auto industry and the PEO employ a systematic team approach to analyze and improve the value of a product, facility design, system, or service. Applying systems engineering principles helps ensure successful execution of the PEO GCS VE program. The auto industry uses VE more widely
Many of the “ilities” (Reliability, Maintainability, etc) are afterthoughts in the creation of a specification, and are often relegated to a set of templated boilerplate requirements, that are largely ignored. The Reliability / Robust Design professionals often use a P-Diagram (Parameter Diagram) as a key part of understanding the system under design. A way of integrating the Reliability effort more into the mainstream of the design activity, and give them a stronger voice, is to put their P-Diagram right into the specification, before it gets released to industry. This paper describes the rationale and the manner in which to do this
ABSTRACT The use of lead-free components in electronic modules destined for defense applications requires a deep understanding of the reliability risks involved. In particular, pad cratering, tin whiskers, shock and vibration, thermal cycling and combined environments are among the top risks. Testing and failure analysis of representative assemblies across a number of scenarios, including with and without risk mitigations, were performed to understand reliability of lead-free assembly approaches, in comparison with leaded and mixed solder approaches. The results lead to an understanding of lead-free reliability and how to improve it, when required. This outcome is resulting in user acceptance of lead-free electronics, which is timely given the increasing scope of lead-free legislation
Advances in IoT and electronic technology are enabling more personalized, continuous medical care. People with medical conditions that require a high degree of monitoring and continuous medication infusion can now take advantage of wearable medicine injection devices to treat their problems. Wireless communication allows medical personnel to monitor and adjust the amount and flow rate of an individual’s medication. The small size of the injectors enables the individual to be active and not be burdened or limited by a line-powered instrument (see Figure 1
American drivers have long been accustomed to quickly filling up at a gas station with plenty of fuel available, and electric vehicle drivers want their pit stops to mimic this experience. Driver uncertainty about access to charging during long trips remains a barrier to broader EV adoption, even as the U.S. strives to combat climate change by converting more drivers
As the U.S. military embraces vehicle electrification, high-reliability components are rising to the occasion to support their advanced electrical power systems. In recent years, electronic device designers have started using wide band-gap (WBG) materials like silicon carbide (SiC) and gallium nitride (GaN) to develop the semiconductors required for military device power supplies. These materials can operate at much higher voltages, perform switching at higher frequencies, and feature better thermal characteristics. Compared to silicon, SiC-based semiconductors provide superior performance. The growing availability of these materials, in terms of access and cost, continues to encourage electrification. With the ever-present pressure of size, weight, and power (SWaP) optimization in military applications, and a desire to keep up with the pace of innovation, there's a need for capacitors that can deliver higher power efficiency, switching frequency, and temperature resistance under harsh
As aerospace engineers push the boundaries of new frontiers, the need for advanced materials that can withstand the rigorous demands of these advanced applications is relentless. These materials go beyond functionality; it is about ensuring reliability in the skies, where failure is not an option. Fluorosilicone can help do exactly that. In the 1960s, the U.S. Air Force noticed that conventional silicone-based sealants, coatings, and other components degraded rapidly when exposed to fuels, de-icing fluids, and other hydrocarbon-based solvents. Dimethyl-based silicones are non-polar and easily absorb hydrocarbon-based solvents, which may result in material swelling, mechanical weakening, and ultimately, failure
For many patients waiting for a donor heart, the only way to live a decent life is with the help of a pump attached directly to their heart. This pump requires about as much power as a TV, which it draws from an external battery via a seven-millimeter-thick cable. The system is handy and reliable, but it has one big flaw: despite medical treatment, the point at which the cable exits the abdomen can be breached by bacteria
Though modal analysis is a common tool to evaluate the dynamic properties of a structure, there are still many individual decisions to be made during the process which are often based on experience and make it difficult for occasional users to gain reliable and correct results. One of those experience-based choices is the correct number and placement of reference points. This decision is especially important, because it must be made right in the beginning of the process and a wrong choice is only noticeable by chance in the very end of the process. Picking the wrong reference points could result in incomplete modal analysis outcomes, as it might make certain modes undetectable, compounded by the user's lack of awareness about these missing modes. In the paper an innovative approach will be presented to choose the minimal number of mandatory reference points and their placement. While other approaches use results of numerical simulations or rely on a visual evaluation of measurement
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