美国国家航空航天局与Wind River Simics达成卫星项目测试和验证目标-客户成功案例

Powerful High-Fidelity Simulator Minimizes Target HardwareDependencies and Brings Significant Long-Term Cost Savings NASA’s Independent Verification and Validation (IV&V) Program wasfounded as part of the agency’s strategy to provide the highest achievablelevels of safety and cost-effectiveness for mission-critical software. Nasa IndustrySpace exploration NASA IV&V’s primary business is software verification and validation. Theprogram has more than 150 full-time employees and also leverages theexpertise of in-house partners and contractors. Solutions •Wind River Simics THE CHALLENGE Results •Reduced risks and costs byeliminating hardware availabilitydelays and bugs earlier in thedevelopment process•Increased quality by introducingautomation, catching show-stopper bugs, and improvingconsistency of hardware setups•Increased engineering efficiencybyfinding andfixing bugs fasterand by enabling more hardware/software co-development•Enabled tremendous long-termcost savings, since 80–90% ofSimics simulation models canbe reused for future missions Rising development and maintenance costs comprise the key business chal-lenge of testing and verification for NASA IV&V. Because of their complexityand stringent safety requirements, most NASA projects take many years tocome to fruition. It wouldn’t be practical to perform traditional hardware-based testing andverification because of the cost of supporting and maintaining the hardware.Too much time and effort would be expended trying to find old boards thatare no longer available in order to run tests. Then there’s the cost of storinginventory and the issues surrounding portability. It’s difficult to replicatehardware for multiple uses. For these reasons, software simulations have recently become essential tothe NASA IV&V test and verification process. In 2010, the NASA IV&V Independent Test Capability (ITC) team joined forceswith NASA Goddard Space Flight Center (GSFC) to develop a software-onlysimulator for the Global Precipitation Measurement (GPM) OperationalSimulator (GO-SIM) project. The GPM mission is an international networkof satellites providing next-generation global observations of rain and snow.GO-SIM includes the GPM ground system and database, flight softwareexecutables, and spacecraft simulators. By using Wind River Simics, 80–90% ofthe simulation models can be reusedfor other missions, representingtremendous cost savings for NASA. Simics is easily and quickly configurable. Setting up aparticular target system is much faster than on hardware.Configurations of the virtual platform can be saved andaccessed at a later point in time, ensuring consistenthardware setups within a development organization andcustomer support situations. Simics also supports rapidprototyping and the ability to quickly determine the impactof a potential hardware change on software performance. GO-SIM was designed as a high-fidelity simulator withno hardware dependencies. Its functions include loadingand running unmodified flight software binaries, executingflight scripts, performing single-step debugging, injectingerrors via the ground system, stressing the system undertest, and validating findings from other analyses. THE SOLUTION Wind River®Simics®, simulating a BAE RAD750 processor,enables target software to run on the virtual platformthe same way it does on physical hardware. Along withSimics’ capabilities of scripting, debugging, inspection,and fault injection, it enables users to define, develop, andintegrate their systems without the constraints of physicaltarget hardware. RESULTS With Simics, NASA IV&V successfully met its goalsto develop a complete simulator with no hardware depen-dencies in a reduced time frame and at lower cost than if ithad been developed using traditional hardware simulations. ITC team members now have test assets available whenthey need them. Government agencies such as NASAtypically buy assets for a five- to 10-year project up front;then by the time they need them, the requirements havechanged and they can’t get the hardware. Wind RiverSimics solved this problem. Engineers don’t have to sit idle,waiting for the physical hardware to show up, before theycan work. Simics allowed NASA’s ITC team to simulate its targethardware, ranging from a single processor to large,complex, and connected electronic systems, and build itsGO-SIM product with all the desired features. Using this virtual environment, the ITC team can adoptapproaches and techniques not possible on physical hard-ware. For example, developers can freeze, save, email, andrestore the whole system; they can view and modify everydevice, register, or memory location; and they can run thewhole system in reverse to find the source of a bug. Simicsequips the ITC team with a risk-reduction toolbox capableof injecting errors anywhere in the system and testingfault-management responses. This improves product qual-ity and engineering efficiency. Simics has enabled NASA IV&V to enha