Design Of Satellite Payload Data Transmission System Based On CAN Bus

With the development of the aerospace and the acceleration of the satellite technology in our country, more and more requirements of the satellite data transmission are demanded for the real time and high reliability performance, to ensure the satellite works well.The research of satellite payload management system is much earlier in abroad,which had worked out a specified CPU with faster speed and higher ability in fault-tolerant. Meanwhile,CAN bus was used for data exchanging in the satellite system as well. In this situation,the states of domestic is falling behind by contrast.Although the CAN bus technology was applied in many satellites presently,the 1553 B bus still work in the data transmission between satellite and payload with higher cost and lower fault-tolerance.Nowadays, the satellite gradually developed as a parallel system with high performance in calculation and redundancy,under the guarantee of the reliability for payload data transmitting.The higher transmission capability and fault-tolerant ability is the development tendency for satellite payload data transmission system currently.This paper reviews the background of satellite and payload,summary the latest development and research in our country and abroad,elaborated on the main job and the structure of this thesis,discuss the satellite data transmission system based on CAN bus technology about several aspects at the first chapter.Firstly, this paper studies advantages of the data bus which has been applied to the satellite. Based on the characteristics of the data transmission system, this paper compares 1553 B bus and CAN buson aspects which are thosecharacteristicsand application on satellite. Based on those comparisons, the transmission system selectsa appropriate serial bus.Due to the design specification of the star loading requires a higher transmission rate and stronger anti-jamming capability, and error detection ability to the transport, so CAN bus act as the communication whichcomplete transmitting and receiving data between the Star service system and the satellite loading.Secondly, the paper analysis the requirementaboutthetransmitting system, and based on functions and constitution of the satellite borne data transmission system, put forward a design scheme on satellite borne data transmission system which can realize on project andmeet requirements of the CAN bus communication protocol specification, and proposes the design goals.According to the demand analysis and the design objective, thisinexpensive satellite borne digital system can be reliable, efficient and flexible to complete digital task.Thirdly, this paper designs units of the data transmission system, which include the central control module,the CAN bus network transmission module,the power module,system reliability designing and so on.According to the function of each module, the circuit is designedand chipsare selected,especially CAN bus network transmission modulewhich is regarded as the core system. Under the premise of ensuring to complete the task of the data transmission, this paper simplifies circuit design,hardware design of. After that,the complexity of the satellite environment is analyzed. Thenaim at the complexity of the operating environment of satellite, the reliability of this data transmission system is analyzed and designed in detail, to ensure the stability and reliability of the data transmission system.Finally,the PC simulates the Star service system transmit star service instruction through the USB-CAN card. The system of transmitting digital receives and analysis star service instructions, then transmit to the loading control unit, or receives loadingand returns distancing measure and transmitsthe Star service system. After, this way completes function test of the digital transmitting system.