The Testing Platform Of Software In Satellite

Software in Satellite, as the key part of whole satellite, is used for control of thesatellite's attitude and orbit and data interactions between platform and load as wellas between control station on satellite and ground. As satellite's subsystem, computeron satellite and the whole satellite system together make up a closed-loop runningsystem and hardly affected by human. Due to working in badly environment andaffected by space high-energy particle, the system's reliability and experiment'sresult depend on whether the software is correct. Therefore this software has to betested. As a third-party testing institution of spaceflight software, the eighthinstitution detecting station is going to set up a separately open-loop simulationtesting platform for satellite attitude and orbit control software to achieve variousfunctional, performance and security testing.Four kinds of basic methods of embedded software simulation platform, whichare full digital simulation, semi-practicality open-loop simulation, semi-practicalityclosed-loop simulation and practicality simulation, are introduced firstly and theiradvantages and disadvantages are analyzed in this paper. According to the presentstatus of testing simulation platform inside/outside China and future development andcombined of the testing station's resources, SHAM and EUROSIM are chosen to bethe basic platform to set up testing simulation platform.SHAM2 used in this paper is a validation device for Processor-in-the-loopsimulation software, based on object processor. It can provide an actual objectprocessor 31750 CPU and a control system. This CPU can run the tested software andsimulate simple interface of hardware and software. The most important characteristicof SHAM is that the object CPU and its related time information can be controlled bycontrol system, so it can be used to establish real functional system software testingenvironment. EUROSIM, which is a simulation environment set-up and run tool withgraphical interface, can realize many functions, such as different kinds of models,relationship between models, model task, and time schedule and so on. Aiming atsatellite attitude and orbit control system, this system uses C-code model, sets up dynamics environment based on EUROSIM, simulates sensitive parts, executive partsand control rules, generates signals and forms testing simulation environment.Basic theory and system instruction of SHAM and EUROSIM, software functionand the difficulty in platform software development are introduced in this paper. Theplatform has passed functional test, security test and data validation functional testand enhanced the verification test method of satellite attitude and orbit controlsoftware.In the end, further development is discussed. The experience of simulationplatform development is accumulated by studying this open-loop testing simulationplatform of satellite attitude and orbit control system software, which can beapplicable for other sequential open-loop testing and a foundation of closed-looptesting.