Modeling Framework and Software Tools for Walking Robots

In research on passive dynamic walking, the aim is to study and design robots that walk naturally, i.e., with little or no control effort. McGeer [1] and others (e.g. [2, 3]) have shown that, indeed, robots can walk down a shallow slope with no actuation, only powered by gravity.\ud In this work, we derive mathematical models of walking ro- bots to better understand the dynamics that determine the walking behavior, and to design controllers that e.g. in- crease robustness against changing environments. We use the port-Hamiltonian framework, as it has the advantage of explicitly showing energy-flows inside and into the system. Thus, it allows a direct efficiency study as well as the possi- bility to connect external elements in a ‘physical’ way using ports, instead of using just torque/force signals

NASA Keynote at the 2015 Trilateral SMA Conference, Frascati, Italy

The purpose of this presentation is to illustrate some new directions within NASA's safety and mission function in response to changes in missions, technology, and practices. The presentation lists last year's highlights from NASA's human and robotic spaceflight missions, and discusses anticipated highlights for the coming year taken from existing Agency presentations. It will highlight changes to NASA's mission and the way NASA does business, as described in the 2014 strategic plan. It will then discuss how these changes pose challenges to trusted SMA practices, and provide some examples of initiatives NASA is taking action to address these challenges

Proposal for a Comparison of Reliability and Maintainability Activities Across ESA, JAXA, and NASA

NASA has developed an objectives based hierarchy for guiding Reliability and Maintainability activities. This presentation overviews the hierarchy and proposes to the international trilateral partners to formulate a task force to consider the elements of the NASA RM framework, as captured in the hierarchy of RM considerations, to identify commonalities and differences in the way reliability and maintainability is addressed by the flight projects among the partners

NASA Human-Rating Requirements

NASA's Procedural Requirements 87052B defines the Human-Rating Certification process and related technical requirements for human spaceflight programs developed by and for NASA. The document specifies Agency-level responsibilities related to the certification, processes to be established by the program, and technical requirements

Fault Management in an Objectives-Based/Risk-Informed View of Safety and Mission Success

Theme of this talk: (1) Net-benefit of activities and decisions derives from objectives (and their priority) -- similarly: need for integration, value of technology/capability. (2) Risk is a lack of confidence that objectives will be met. (2a) Risk-informed decision making requires objectives. (3) Consideration of objectives is central to recent guidance

The Evolution of System Safety at NASA

The NASA system safety framework is in the process of change, motivated by the desire to promote an objectives-driven approach to system safety that explicitly focuses system safety efforts on system-level safety performance, and serves to unify, in a purposeful manner, safety-related activities that otherwise might be done in a way that results in gaps, redundancies, or unnecessary work. An objectives-driven approach to system safety affords more flexibility to determine, on a system-specific basis, the means by which adequate safety is achieved and verified. Such flexibility and efficiency is becoming increasingly important in the face of evolving engineering modalities and acquisition models, where, for example, NASA will increasingly rely on commercial providers for transportation services to low-earth orbit. A key element of this objectives-driven approach is the use of the risk-informed safety case (RISC): a structured argument, supported by a body of evidence, that provides a compelling, comprehensible and valid case that a system is or will be adequately safe for a given application in a given environment. The RISC addresses each of the objectives defined for the system, providing a rational basis for making informed risk acceptance decisions at relevant decision points in the system life cycle

An Extreme-Value Approach to Anomaly Vulnerability Identification

The objective of this paper is to present a method for importance analysis in parametric probabilistic modeling where the result of interest is the identification of potential engineering vulnerabilities associated with postulated anomalies in system behavior. In the context of Accident Precursor Analysis (APA), under which this method has been developed, these vulnerabilities, designated as anomaly vulnerabilities, are conditions that produce high risk in the presence of anomalous system behavior. The method defines a parameter-specific Parameter Vulnerability Importance measure (PVI), which identifies anomaly risk-model parameter values that indicate the potential presence of anomaly vulnerabilities, and allows them to be prioritized for further investigation. This entails analyzing each uncertain risk-model parameter over its credible range of values to determine where it produces the maximum risk. A parameter that produces high system risk for a particular range of values suggests that the system is vulnerable to the modeled anomalous conditions, if indeed the true parameter value lies in that range. Thus, PVI analysis provides a means of identifying and prioritizing anomaly-related engineering issues that at the very least warrant improved understanding to reduce uncertainty, such that true vulnerabilities may be identified and proper corrective actions taken

Precursor Analysis for Flight- and Ground-Based Anomaly Risk Significance Determination

This slide presentation reviews the precursor analysis for flight and ground based anomaly risk significance. It includes information on accident precursor analysis, real models vs. models, and probabilistic analysis

Status of Commercial Programs at NASA

NASA's strategy is two-fold: (1) Use Space Act Agreements to support the development of commercial crew transportation capabilities. (2) Use FAR-based contracts for the certification of commercially developed capabilities and for the procurement of crew transportation services to and from the ISS to meet NASA requirements. Focus is on reducing the risk and uncertainties of the development environment and on the incentives provided through competition by separating the design and early development content from the longer-term CTS Certification activities. CCP expects to develop, demonstrate, and certify U.S. commercial crew space transportation capabilities that meet ISS crew transportation needs by the end of FY 2017

Perspective on Probabilistic Methods for Safety and Reliability Assessments

No abstract availabl