Practical Application of MBSE to Early Phase Space System Development

Transcription

1 DLR.de Chart 1 > PRACTICAL APPLICATION OF MBSE TO SPACE SYSTEM DEVELOPMENT > M Kretzenbacher Practical Application of MBSE to Early Phase Space System Development Professional Thesis Project Michael Kretzenbacher, 2016

2 DLR.de Chart 2 > PRACTICAL APPLICATION OF MBSE TO SPACE SYSTEM DEVELOPMENT > M Kretzenbacher Project Background

3 DLR.de Chart 3 > PRACTICAL APPLICATION OF MBSE TO SPACE SYSTEM DEVELOPMENT > M Kretzenbacher Project Context Project was part 5 Month in-industry placement as required for the completion of the advanced masters degree in Space Systems Engineering at ISAE- SUPAERO. Project was supported by Shoal through MBSE expertise and training, Vitech Corporation through use of GENESYS 4 and discussion and the DLR through access to the S2TEP Project and domain expertise. Project took place in the context of the S2TEP project at the DLR. The Small Satellite Technology Platform (S2TEP) project seeks to build a cost effective micro-satellite platform for in-orbit technology demonstration and to serve small scientific payloads. DLR is utilising a model based approach throughout the development of S2TEP.

4 DLR.de Chart 4 > PRACTICAL APPLICATION OF MBSE TO SPACE SYSTEM DEVELOPMENT > M Kretzenbacher Research Questions Core research question: What value can be added by practically applying MBSE to the process of developing a space system at the DLR? Project explored the use of 2 types of models. Models can be categorised as being descriptive or analytic (Long, 2016). Descriptive models act as both the model and specification for the system of interest. Analytic models are discipline or domain specific models representing key performance characteristics and constraints that govern system

5 DLR.de Chart 5 > PRACTICAL APPLICATION OF MBSE TO SPACE SYSTEM DEVELOPMENT > M Kretzenbacher Approach Project Aims: Explore what value MBSE could add to spacecraft development. Find applications and features that could be used in DLR MBSE approaches i.e. further evolution of DLR VirSat tool. Project Approach Model a generic spacecraft template model in GENESYS. Create descriptive model of S2TEP in GENESYS using output from a Concurrent Engineering study and template model. Add analytic model aspects to S2TEP Model using GENESYS simulation abilities.

6 DLR.de Chart 6 > PRACTICAL APPLICATION OF MBSE TO SPACE SYSTEM DEVELOPMENT > M Kretzenbacher Generic Spacecraft Template

7 DLR.de Chart 7 > PRACTICAL APPLICATION OF MBSE TO SPACE SYSTEM DEVELOPMENT > M Kretzenbacher Generic Spacecraft Model Scope Model of a non-specific spacecraft Aim was to create a template that could be used to rapidly start system models of future systems. Hypothesis space systems share core functions and so are similar enough to have a common template.

8 DLR.de Chart 8 > PRACTICAL APPLICATION OF MBSE TO SPACE SYSTEM DEVELOPMENT > M Kretzenbacher Generic Spacecraft Model - View of System Structure Heirarchy Diagram

9 DLR.de Chart 9 > PRACTICAL APPLICATION OF MBSE TO SPACE SYSTEM DEVELOPMENT > M Kretzenbacher Generic Spacecraft Template Results Keeping the spacecraft generic was difficult. Reality accommodating different system architectures is challenging. Somewhat useful in facillitating project beginning. Provides some guidance in system model architecture. Template may better serve projects if more limited in spacecraft type.

10 DLR.de Chart 10 > PRACTICAL APPLICATION OF MBSE TO SPACE SYSTEM DEVELOPMENT > M Kretzenbacher S2TEP Model Descriptive Modelling

11 DLR.de Chart 11 > PRACTICAL APPLICATION OF MBSE TO SPACE SYSTEM DEVELOPMENT > M Kretzenbacher S2TEP Model Structure and Traceability Heirarchy Diagram Component Relationships

12 DLR.de Chart 12 > PRACTICAL APPLICATION OF MBSE TO SPACE SYSTEM DEVELOPMENT > M Kretzenbacher S2TEP Structure Flow Interfaces at Different Levels of Decomposition

13 DLR.de Chart 13 > PRACTICAL APPLICATION OF MBSE TO SPACE SYSTEM DEVELOPMENT > M Kretzenbacher S2TEP Behaviour Operational Modelling Enhanced Function Flow Block Diagrams (EFFBD)

14 DLR.de Chart 14 > PRACTICAL APPLICATION OF MBSE TO SPACE SYSTEM DEVELOPMENT > M Kretzenbacher S2TEP Descriptive Modelling Central source of common system design knowledge avoids information siloing. Model can be displayed in HTML as read only system information source. Operational modelling allows for earlier introduction of spacecraft operations domain specialists. Operational modelling creates new degree of freedom for design equipment usage time is now a considered performance parameter.

15 DLR.de Chart 15 > PRACTICAL APPLICATION OF MBSE TO SPACE SYSTEM DEVELOPMENT > M Kretzenbacher S2TEP Model Analytic Modelling

16 DLR.de Chart 16 > PRACTICAL APPLICATION OF MBSE TO SPACE SYSTEM DEVELOPMENT > M Kretzenbacher S2TEP Analytic Modelling System Concept Simulator The chosen application to explore analytic model was the System Concept Simulator (SCS). The SCS is described in the European Cooperation for Space Standardisation (ECSS) Technical Memorandum (TM) on System Modelling and Simulation, ECSS-E-TM-10-21A. The SCS supports the trade-off for system concepts in an iterative process, by providing a quantitative assessment of the system performance for concepts. The SCS is intended to support decisions on mission or system trades.

17 DLR.de Chart 17 > PRACTICAL APPLICATION OF MBSE TO SPACE SYSTEM DEVELOPMENT > M Kretzenbacher System Concept Simulator Output Resource Usage Analysis Time (min) Orbit With High Power Consumption Available power in Batteries Sunlight Eclipse Time (min) Orbit With Low Power Consumption Available power in Batteries Sunlight Eclipse Combining Power Modes Time (min) Available Power in Batteries High Power Low Power Low Power

18 DLR.de Chart 18 > PRACTICAL APPLICATION OF MBSE TO SPACE SYSTEM DEVELOPMENT > M Kretzenbacher Results, Discussion and Conclusion

19 DLR.de Chart 19 > PRACTICAL APPLICATION OF MBSE TO SPACE SYSTEM DEVELOPMENT > M Kretzenbacher Challenges and Limitations Inability to test the application of MBSE to the critical path of space system development. As a result modelling was done backwards components > behaviour > requirements. Operational modelling was overly simplistic. Estimation of value added through a shadow model utilised in a brief system development window could only be qualitative and speculative.

20 DLR.de Chart 20 > PRACTICAL APPLICATION OF MBSE TO SPACE SYSTEM DEVELOPMENT > M Kretzenbacher Conclusions MBSE adds value by facillitating a more robust preliminary design. By assisting the monitoring of change propagation, aiding requirements tracking and traceability, earlier inclusion of operations and early modelbased validation, MBSE can allow the preliminary design to match the user needs more closely. MBSE is best practically applied by placing the model at the centre of the project. Model should be placed on the critical path throughout the project life. Good proof of concept application to small scope projects i.e. Cubesats / Microsats. Student projects may also be a good low risk application. The main continued value of MBSE to the entire lifecycle is the improved knowledge capture and communication as well as the more robust design.

21 DLR.de Chart 21 > PRACTICAL APPLICATION OF MBSE TO SPACE SYSTEM DEVELOPMENT > M Kretzenbacher Key Lessons Learned A key lesson learned was that fully applied MBSE is not just a model tacked on to a project - The model should be used to shape the design from the beginning of the project. To gain full benefit from the central source of common knowledge, MBSE should be a team effort. The development of effective metrics for measuring MBSE value is important.

22 DLR.de Chart 22 > PRACTICAL APPLICATION OF MBSE TO SPACE SYSTEM DEVELOPMENT > M Kretzenbacher Thank You / Merci / Danke