A Design Of Micro-nano Satellite Simulator

"Micro-nano satellite" is a general term for a class of artificial satellites weighing less than 100 kg.Among them,the weight of a "microsatellite" is generally less than 100 kg,and the weight of a typical "nanosatellite" is generally less than 10 kg.The popular concept of "Cube Sat" belongs to the category of micro-nano satellites.With the current rapid development of the electronics industry,the successful commercialization of space launches and the maturity of the satellite manufacturing industry,it is possible for universities and research institutions to take part in the development of micro-nano satellites themselves.However,the development of micro-nano satellites for students and junior researchers is still in the status quo where each mission and researching are start from scratch.For those researchers who are trying to have a taste of the manufacture and development process of micro-nano satellites,it is vital to provide a representative primary micro-nano satellite development platform.This paper proposes a Cube Sat simulator,which similar to the electrical structure for Cube Sat manufactured with commercial components(COTS)and automotive grade and industrial grade components,and a mechanizm to simulate orbital electrical parameters was achieved on the basis of previous work.The failure analysis test could also be achieved by this system.It can be seen as a kind of "Cube Sat development board",on this platform,users can experience the general process of micro-nano satellite application development and how to deal with some typical states of micro-nano satellites in orbit.This article has completed the following work:By abstracting the basic structure of the micro-nano satellite,the overall structure of the satellite was designed,and the design goal of the simulator was determined.On this basis,a 1U cubic star onboard electronic system was designed and implemented.The hardware of the system consists of a satellite onboard computer(OBC),a demonstrative satellite payload and a satellite power supply system board.Each part is composed of a standard 1U cubic star circuit board.Following features have been developed: The hot backup of the on-board computer,the topology of the on-board bus,the driver of the sun sensor and the camera,and the power supply and management of the other subboard.The software part adopts the Free RTOS embedded real-time operating system,and correspondingly developed the system-level service process that serves the user program,it packed the built-in functions and components of the system as well as the hardware driver and processing function,which provides a basis for user level development.When developing user-level applications on this system,all applications can obtain the system status and perform corresponding logical operations without directly operating the hardware by calling the interface and accessing the registers provided by the system.By analyzing the status and environmental characteristics of a satellite in orbit may face,a test system for failure analysis of micro-nano satellites was designed and achieved.Through this test system,the user can use the control software on the personal computer to upload instructions to the satellite simulator to simulate the satellite circumstances such as electronic system working status and accidental failure.One can check the working status and debugging information of each sub-board through the debugging interface.These simulations provide a debugging environment for the user’s development,so that the user can simulate the program processing in several typical scenarios without setting up a real test environment,and check whether the program response is normal and appropriate.Through the work described in this paper,the design and production of the micro-nano satellite simulator was finally completed,and the failure analysis test system of the micro-nano satellite was developed.After testing,it meets the design requirements and expected goals.