Bidirectional Graphical Modelling Supporting Concurrent Spacecraft Design

A graphical representation of the system under design in form of diagrams is a powerful way to present complex relationships. Diagrams appear in almost every concurrent design activity in some way sooner or later in the process. Generally they help to explain the design or give an overview so that the other stakeholders can quickly understand a (sub-) system build-up or a proposed solution. Furthermore diagrams are also important for documentation purposes (presentations, reports, interface control documents). Typically the diagrams are made in some external tool and the content is not linked to the constantly changing system model. Especially considering the fast pace of concurrent design studies, such diagrams become quickly inconsistent and outdated, thus breaking the model-based paradigm. This is the motivation for the work presented in this paper to include basic support for graphical modeling within the Model-based System Engineering tool called Virtual Satellite. The paper presents three different diagram types, explains their content and relevance for concurrent engineering sessions. It further mentions implementation details and the used technologies to include bidirectional graphical modeling editors in the Virtual Satellite software

Development of a concurrent engineering tutorial as part of the “ESA_Lab@” initiative

As part of the “ESA_Lab@" initiative, a Concurrent Engineering facility has been constructed at the Mechanical Engineering department of Technical University Darmstadt. Concurrent Engineering is a well-proven concept for designing complex space systems and missions in the pre-phase 0/A mission phase. The Concurrent Engineering methodology and processes are enabled by a multidisciplinary team and specific infrastructure in terms of both hardware and software, which generate an effective and time efficient design management system. The university’s “Concurrent Engineering Lab” provides an environment for both researchers and students to explore and apply the Concurrent Engineering approach in areas such as (model-based) systems engineering, Industry 4.0/ Space 4.0, and space traffic management. Furthermore, collaboration with the European Space Operations Centre – also located in Darmstadt – regarding the application of Concurrent Engineering for Ground Segment & Operations has been started. The first addition to the university’s curriculum centered around the Concurrent Engineering Lab will be a “Concurrent Engineering Tutorial”, an opportunity to introduce the Concurrent Engineering methods and tools via hands-on experience to students of the newly established master’s degree program “Aerospace Engineering”. “Tutorials” are elective block courses of the degree program which offer practical learning experiences in many different fields, awarding 4 credit points upon successful completion. Building on the lectures "Fundamentals of Space Systems" and "Space Systems and Space Operations", the week-long “Concurrent Engineering Tutorial” will challenge students to use their acquired knowledge to develop a preliminary design for a predefined CubeSat mission. This Tutorial will not only provide a closer understanding of the individual subsystems of the space segment of a mission, the Concurrent Engineering process and the relevant software “COMET” by RHEA Group but will also create a synergy with a student association of the university, as one of their projects is the development of a CubeSat. This paper describes the background and approach to the development of the Tutorial, in particular the structure of the re-usable model architecture in “COMET”, which was specifically derived and implemented for this purpose and validated via a pilot stud

A concurrent engineering approach to develop BioMEMS employed in a deep brain stimulator integrated with a drug delivery system

This paper presents an Integrated Product Development (IPD) based model to specifically develop bio-medical micro-electro-mechanical-systems (BioMEMS). The concurrent engineering model is based on the IPD model phases, which are presented and formulated by the Integration DEFinition (IDEF) model- ling language. To evaluate the IPD model, a case study concerning the development of a BioMEMS device for a deep brain stimulation (DBS) system was investigated. By following the relevant mechanisms and controls in the model, a design concept of a wireless head-mounted DBS implant integrated with a drug delivery system (DDS) was conceived. The contribution of this paper is the IDEF model, which provides a road map to the product development team members in order to take a concurrent engineering approach to develop Bio-MEMS. The qualitative feedback received from the identified stakeholders, together with the quality of the case study employed, namely, an integrated DBS and DDS solution, indicate a degree of evidence that the model provides a sound basis in this direction.peer-reviewe

Model-Based Systems Engineering in Concurrent Engineering Centers

Concurrent Engineering Centers (CECs) are specialized facilities with a goal of generating and maturing engineering designs by enabling rapid design iterations. This is accomplished by co-locating a team of experts (either physically or virtually) in a room with a focused design goal and a limited timeline of a week or less. The systems engineer uses a model of the system to capture the relevant interfaces and manage the overall architecture. A single model that integrates other design information and modeling allows the entire team to visualize the concurrent activity and identify conflicts more efficiently, potentially resulting in a systems model that will continue to be used throughout the project lifecycle. Performing systems engineering using such a system model is the definition of model-based systems engineering (MBSE); therefore, CECs evolving their approach to incorporate advances in MBSE are more successful in reducing time and cost needed to meet study goals. This paper surveys space mission CECs that are in the middle of this evolution, and the authors share their experiences in order to promote discussion within the community

Model-Based Systems Engineering in Concurrent Engineering Centers

Concurrent Engineering Centers (CECs) are specialized facilities with a goal of generating and maturing engineering designs by enabling rapid design iterations. This is accomplished by co-locating a team of experts (either physically or virtually) in a room with a narrow design goal and a limited timeline of a week or less. The systems engineer uses a model of the system to capture the relevant interfaces and manage the overall architecture. A single model that integrates other design information and modeling allows the entire team to visualize the concurrent activity and identify conflicts more efficiently, potentially resulting in a systems model that will continue to be used throughout the project lifecycle. Performing systems engineering using such a system model is the definition of model-based systems engineering (MBSE); therefore, CECs evolving their approach to incorporate advances in MBSE are more successful in reducing time and cost needed to meet study goals. This paper surveys space mission CECs that are in the middle of this evolution, and the authors share their experiences in order to promote discussion within the community

Model-Based Systems Engineering for System Safety: An Introduction

Model-based systems engineering (MBSE) has gained momentum as the predominant method of analyzing and deriving system requirements, as well as of verifying and validating system performance. Over the years, several frameworks have gained prominence as approved methods and formal techniques to model systems. MBSE technology continues to gain popularity within the systems engineering domain, especially in markets of complex systems. To remain relevant within the context of concurrent engineering, it is advantageous for system safety engineers to learn how these techniques are affecting system design so that safety is addressed within system development. This paper provides an overview of MBSE in theory and practice, and provides high-level details on how the system safety engineer can use these methods for optimum impact in affecting safety design

Comparing metaheuristic algorithms for error detection in Java programs

Chicano, F., Ferreira M., & Alba E. (2011). Comparing Metaheuristic Algorithms for Error Detection in Java Programs. In Proceedings of Search Based Software Engineering, Szeged, Hungary, September 10-12, 2011. pp. 82–96.Model checking is a fully automatic technique for checking concurrent software properties in which the states of a concurrent system are explored in an explicit or implicit way. The main drawback of this technique is the high memory consumption, which limits the size of the programs that can be checked. In the last years, some researchers have focused on the application of guided non-complete stochastic techniques to the search of the state space of such concurrent programs. In this paper, we compare five metaheuristic algorithms for this problem. The algorithms are Simulated Annealing, Ant Colony Optimization, Particle Swarm Optimization and two variants of Genetic Algorithm. To the best of our knowledge, it is the first time that Simulated Annealing has been applied to the problem. We use in the comparison a benchmark composed of 17 Java concurrent programs. We also compare the results of these algorithms with the ones of deterministic algorithms.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. This research has been partially funded by the Spanish Ministry of Science and Innovation and FEDER under contract TIN2008-06491-C04-01 (the M∗ project) and the Andalusian Government under contract P07-TIC-03044 (DIRICOM project)

Digital Availability of Product Information for Collaborative Engineering of Spacecraft

In this paper, we introduce a system to collect product information from manufacturers and make it available in tools that are used for concurrent design of spacecraft. The planning of a spacecraft needs experts from different disciplines, like propulsion, power, and thermal. Since these different disciplines rely on each other there is a high need for communication between them, which is often realized by a Model-Based Systems Engineering (MBSE) process and corresponding tools. We show by comparison that the product information provided by manufacturers often does not match the information needed by MBSE tools on a syntactic or semantic level. The information from manufacturers is also currently not available in machine-readable formats. Afterwards, we present a prototype of a system that makes product information from manufacturers directly available in MBSE tools, in a machine-readable way.Comment: accepted at CDVE201

Controlling Concurrent Change - A Multiview Approach Toward Updatable Vehicle Automation Systems

The development of SAE Level 3+ vehicles [{SAE}, 2014] poses new challenges not only for the functional development, but also for design and development processes. Such systems consist of a growing number of interconnected functional, as well as hardware and software components, making safety design increasingly difficult. In order to cope with emergent behavior at the vehicle level, thorough systems engineering becomes a key requirement, which enables traceability between different design viewpoints. Ensuring traceability is a key factor towards an efficient validation and verification of such systems. Formal models can in turn assist in keeping track of how the different viewpoints relate to each other and how the interplay of components affects the overall system behavior. Based on experience from the project Controlling Concurrent Change, this paper presents an approach towards model-based integration and verification of a cause effect chain for a component-based vehicle automation system. It reasons on a cross-layer model of the resulting system, which covers necessary aspects of a design in individual architectural views, e.g. safety and timing. In the synthesis stage of integration, our approach is capable of inserting enforcement mechanisms into the design to ensure adherence to the model. We present a use case description for an environment perception system, starting with a functional architecture, which is the basis for componentization of the cause effect chain. By tying the vehicle architecture to the cross-layer integration model, we are able to map the reasoning done during verification to vehicle behavior