Lean Aerospace Initiative (LAI) MIT Research Studies Applicable to Systems Engineering

This publication contains abstracts for past research thesis projects related to systems engineering completed within the LAI research group at Massachusetts Institute of Technology

Probabilistic resource allocation system with self-adaptive capability

A probabilistic resource allocation system is disclosed containing a low capacity computational module (Short Term Memory or STM) and a self-organizing associative network (Long Term Memory or LTM) where nodes represent elementary resources, terminal end nodes represent goals, and weighted links represent the order of resource association in different allocation episodes. Goals and their priorities are indicated by the user, and allocation decisions are made in the STM, while candidate associations of resources are supplied by the LTM based on the association strength (reliability). Weights are automatically assigned to the network links based on the frequency and relative success of exercising those links in the previous allocation decisions. Accumulation of allocation history in the form of an associative network in the LTM reduces computational demands on subsequent allocations. For this purpose, the network automatically partitions itself into strongly associated high reliability packets, allowing fast approximate computation and display of allocation solutions satisfying the overall reliability and other user-imposed constraints. System performance improves in time due to modification of network parameters and partitioning criteria based on the performance feedback

Probabilistic resource allocation system with self-adaptive capability

A probabilistic resource allocation system is disclosed containing a low capacity computational module (Short Term Memory or STM) and a self-organizing associative network (Long Term Memory or LTM) where nodes represent elementary resources, terminal end nodes represent goals, and directed links represent the order of resource association in different allocation episodes. Goals and their priorities are indicated by the user, and allocation decisions are made in the STM, while candidate associations of resources are supplied by the LTM based on the association strength (reliability). Reliability values are automatically assigned to the network links based on the frequency and relative success of exercising those links in the previous allocation decisions. Accumulation of allocation history in the form of an associative network in the LTM reduces computational demands on subsequent allocations. For this purpose, the network automatically partitions itself into strongly associated high reliability packets, allowing fast approximate computation and display of allocation solutions satisfying the overall reliability and other user-imposed constraints. System performance improves in time due to modification of network parameters and partitioning criteria based on the performance feedback

An Analysis of Multiple Layered Networks

Current infrastructure network models of single functionality do not typically account for the interdependent nature of infrastructure networks. Infrastructure networks are generally modeled individually, as an isolated network or with minimal recognition of interactions. This research develops a methodology to model the individual infrastructure network types while explicitly modeling their interconnected effects. The result is a formulation built with two sets of variables (the original set to model infrastructure characteristics and an additional set representing cuts of interdependent elements). This formulation is decomposed by variable type using Benders Partitioning and solved to optimality using a Benders Partitioning algorithm. Current infrastructure network models of single functionality do not typically account for the interdependent nature of infrastructure networks, Infrastructure networks are generally modeled individually, as an isolated network or with minimal recognition of interactions, This research develops a methodology to model the individual infrastructure network types while explicitly modeling their interconnected effects, The result is a formulation built with two sets of variables (the original set to model infrastructure characteristics and an additional set representing cuts of interdependent elements) This formulation is decomposed by variable type using Benders\u27 Partitioning and solved to optimality using a Benders\u27 Partitioning algorithm

Design of an integrated airframe/propulsion control system architecture

The design of an integrated airframe/propulsion control system architecture is described. The design is based on a prevalidation methodology that uses both reliability and performance. A detailed account is given for the testing associated with a subset of the architecture and concludes with general observations of applying the methodology to the architecture

Programmable Logic Device (PLD) Safety Design Approach

Programmable Logic Devices (PLDs) in ordnance fuze and ignition systems have well-defined design and verification requirements based on U.S. Department of Defense (DoD) Safety Review Board guidelines and military standards. However, there are few established safety design and verification requirements for PLDs used in non-fuze safety-significant applications. The primary objective of this paper is to (1) establish a process that assures that PLDs in products and systems are developed and tested to a level of rigor commensurate with the safety risk of the specified application, including fuze and non-fuze safety systems, and (2) to comply with recent guidance from DoD Software System Safety Technical Review Panels on firmware and programmable logic safety assurance. The paper’s secondary objective is to make the PLD safety process applicable to non-DoD and commercial programs such as autonomous vehicles, aerospace and energy systems. To meet this objective, this document incorporates best practices of NASA, commercial aviation, the Nuclear Regulatory Commission (NRC), and from international programmable electronic functional safety standards

Technical Workshop: Advanced Helicopter Cockpit Design

Information processing demands on both civilian and military aircrews have increased enormously as rotorcraft have come to be used for adverse weather, day/night, and remote area missions. Applied psychology, engineering, or operational research for future helicopter cockpit design criteria were identified. Three areas were addressed: (1) operational requirements, (2) advanced avionics, and (3) man-system integration

AFTI/F-16 flight test results and lessons

The advanced fighter technology integration (AFTI) F-16 aircraft is a highly complex digital flight control system integrated with advanced avionics and cockpit. The use of dissimilar backup modes if the primary system fails requires the designer to trade off system simplicity and capability. The tradeoff is evident in the AFTI/F-16 aircraft with its limited stability and fly by wire digital flight control systems when a generic software failure occurs the backup or normal mode must provide equivalent envelop protection during the transition to degraded flight control. The complexity of systems like the AFTI/F-16 system defines a second design issue, which is divided into two segments: (1) the effect on testing, (2) and the pilot's ability to act correctly in the limited time available for cockpit decisions. The large matrix of states possible with the AFTI/F-16 flight control system illustrates the difficulty of both testing the system and choosing real time pilot actions. The third generic issue is the possible reductions in the user's reliability expectations where false single channel information can be displayed at the pilot vehicle interface while the redundant set remains functional

Virtual HR Departments: Getting Out of the Middle

In this chapter, we explore the notion of virtual HR departments: a network-based organization built on partnerships and mediated by information technologies in order to be simultaneously strategic, flexible, cost-efficient, and service-oriented. We draw on experiences and initiatives at Merck Pharmaceuticals in order to show how information technology in establishing an infrastructure for virtual HR. Then, we present a model for mapping the architecture of HR activities that includes both internal and external sourcing options. We conclude by offering some recommendations for management practice as well as future research