PARIS Ė MathWorks said Swedish Space Corporation (SSC) has licensed Model-Based Design with MATLAB and Simulink to develop advanced autonomous formation flying software.
By using MathWork's Model-Based Design, SSC said it has reduced by 50 percent the development of its Prisma project, which tests and validates the guidance, navigation and control (GNC) system.
MathWork's tools for Model-Based Design (See figure) are meant to design, simulate and implement the control system.
Rather than relying on physical prototypes and textual specifications, Model-Based Design uses a system model as an executable specification throughout development. It supports system- and component-level design and simulation, automatic code generation, and continuous test and verification.
Figure: MathWork's Model-Based Design
SSC said it has deployed Model-Based Design with MATLAB and Simulink to help model and simulate the GNC system, perform real-time closed-loop simulations, and generate production flight code. The Prisma project is led by the SSC in collaboration with the French and German space agencies and the Technical University of Denmark.
The Prisma project uses two satellites, Mango and Tango, to demonstrate autonomous formation flying and autonomous rendezvous and proximity operations.
SSC engineers required new GNC algorithms to take advantage of the advanced sensors and propulsion systems of the satellites. They used MATLAB, Simulink, and Stateflow to develop GNC algorithms, run and verify system-level closed-loop simulations in real-time, and generate flight code for both satellites. To rehearse actual mission flight operations and verify flight command sequences, SSC ran simulations against plant model on xPC Target. The team also used MATLAB Compiler to build standalone applications for displaying and analyzing satellite flight data.
"Traditionally, control engineers specify requirements using text and diagrams and someone else codes the software," commented Ron Noteborn, lead engineer at SSC. "With Model-Based Design, we eliminate that step. We work with models from concept to implementation, and we have the automatically generated code flying in space."
Engineers also reused the SMART-1 satellite attitude control models and were able to run tests very early on and reuse those same tests throughout development of the Prisma project. This approach helped to cut development time.
Figure: First in-orbit image of Tango