Control software of the interface device of the satellite service channel
Technical cybernetics. Information technology. Computer facilities
1. Moscow Aviation Institute (National Research University), 4, Volokolamskoe shosse, Moscow, А-80, GSP-3, 125993, Russia
2. Scientific Research Institute, 125, Varshavskoe shosse, Moscow, 117587, Russia
There are the aspects of control software development of the interface device considered in this work. The interface device is a part of the onboard equipment of the satellite service control channel and this device plays key role in the controlling the satellite from the ground control station. The main functions of the interface device is receiving messages from the ground control station and sending telemetry data to ground station. Additionally the device must receive and handle the control signals from satellite onboard apparatus. The interface device consists of hardware and software. The most important functions are performed by the control software.
The previous versions of the satellite also contained interface device. However from version to version the functions of interface device are becoming more complex and the amount of functions is also increasing. Therefore control software development of the new version of the interface device is an actual issue.
In previous versions of interface device functions were performed consequently according to a predetermined cyclogram. But by increasing complexity and amount of the tasks performing by the interface device there is a need to consider the new approaches in the organization of the computational process including approaches using real-time operation systems. It was decided to develop the control software of the new interface device with using the real-time operating system, which is based on the modular concept and the blackboard style.
The using of this operating system allows to split the whole control software into separate modules. Each module can be developed and used relatively independently of the rest modules. The blackboard concept allows to degree the amount of interactive interfaces between modules of the control software. The modules interact with each other only by using the global database called blackboard. The selected operating system also provides ways of flexible priority assignment and performing mode configuration of the different modules of the control program that allows to free up the CPU time of the interface device microprocessor and to meet the specified time limits. These facilities allow to increase functionality of the interface device or to modify the existing functions of the device in the short term.
There was performed self-contained debugging of the control software to verify correct operation of the separate modules. Testing and debugging software by using simulator of external connections showed the correct functioning of the whole interface device in the near-real conditions.
Keywords:interface device, satellite, control software, real time operating system, «blackboard» style, telemetry, simulator of external connections
- Burdonov I.B., Kosachev A.S., Ponomarenko V.N. Operacionnye sistemy real'nogo vremeni (Real-time operating system), Moscow, Institut sistemnogo programmirovanija RAN, 2006, 98p.
- Cameron Hughes, Tracy Hughes. Parallel'noe i raspredelennoe programmirovanie na C++ (Parallel and distributed programming C++), Moscow, Vil'jams, 2004, 672 p.
- Rudenko D. and Borisov. A. An overview of blackboard architecture application for real tasks.Scientific proceedings of Riga technical university, Information Technology and Management Science, Issue 5, 2007, vol.31, RTU, Riga, pp. 50-56.
- Green Hills Software, Inc. MULTI: Debugging. Inc. Green Hills Software, 2004, 969 p.