Optics Program Simplifies Analysis and Design
Monday, 14 April 2008
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The system can be optimized for performance; design parameters can be traded; parameter uncertainties can be propagated through the math model to develop error bounds on system predictions; and the model can be updated, based on component, subsystem, or system-level data.
One of many segments of the mirror assembly being tested for the James Webb Space Telescope project at the X-Ray Calibration Facility at Marshall Space Flight Center. Marshall is supporting Goddard Space Flight Center in developing the telescope by taking numerous measurements to predict its future performance.
The Toolbox allows the definition of process parameters as explicit functions of the coupled model, further enabling the exact definition of sensitivities. It also includes a number of functions that analyze the coupled system model and provide for redesign, including: critical parameter analysis that formally identifies the design variables that have the highest influence on system performance, risk, and cost; optimization of design objective functions subject to constraints on design variables; formal system trading using an isoperformance methodology (a design concept that seeks to create the best-fit concept) that maps out the non-unique set of design parameters that meet requirements; uncertainty analysis for computing errors bound to performance predictions and identifying critical uncertainties; and model updating to renew component math models using measurement data.
The software has myriad benefits, including the ability to automatically couple the discipline models to create a system math model. This provides a complete description of the physical process in terms of all component design variables. The automatic coupling reduces manual effort, eliminates the chance for user error, and automatically checks unit compatibility between components.
The software tool provides a set of “canned” routines for defining parameter dependencies on typical structural parameters, as well as a set of techniques for identifying critical design parameters.
A Marshall Space Flight Center employee is inspecting one of the mirror assemblies for flaws.
The unique formulation of the parameter-dependent math model enables the designer to formulate many problems as formal optimization analyses, where other analysis techniques would have allowed only the evaluation and comparison of a limited set of design points.
The product is being sold commercially by Nightsky Systems Inc., of Raleigh, North Carolina, a spinoff company that was formed by Midé specifically to market the DOCS Toolbox.
Commercial applications include use by any contractors developing large space-based optical systems, including Lockheed Martin Corporation, The Boeing Company, and Northrup Grumman Corporation, as well as companies providing technical audit services, like General Dynamics Corporation.
DOCS® Toolbox is a registered trademark of Nightsky Systems Inc.