The objective of this activity is the development of a CAN bus solution to be used in platform and payload avionics of telecom satellites. The proposed CAN solution has to cover all the aspects related to the introduction of the CAN bus in telecom satellites, from the physical and protocol layer definition up to the test and validation procedure definition.
Key project challenges:
Technical benefits: The CAN bus is a full European technology used since years in the automotive industry, it offers the same reliability of other bus standards like the MIL-1553 offering high saving in the overall power consumption (1/10 of the mil-1553) without any ITAR restriction. It has been selected as alternative of the OBDH bus with significant savings in spacecraft mass due to reduction in number of wires. Furthermore, the capability to manage up to 128 nodes on the same CAN bus, is seen as a major advantage over the existing legacy buses.
Economical Benefits: large availability of low cost commercial and high grade components thanks to its utilization in several different industrial environments. For the same reasons test equipment and development tools are also available at lower cost. Thanks to the higher frequency of the bus the duration of the spacecraft, test campaign duration is reduced with overall benefits in the spacecraft test schedule and cost.
Upgraded Spacebus NEO avionics dedicated to the payload bus implemented with the CAN bus. The following key features have been implemented:
Two different physical layers have been analysed and implemented according the CABCOM study requirements:
The upgraded Spacebus Neo avionics architecture replaces the OBDH lines dedicated to the payload busses with the CAN bus. The high-level payload bus performances have been therefore inherited from the Spacebus 4000 requirements.
As a First Task, the system requirements for a robust CAN solution for SATCOM have been defined.
Second Task focused on the inclusion of a standard protocol layer implementation and its impact on the overall SATCOM architecture.
The Third task, focused on the design, implementation and justification of the selected CAN bus solution and its test set-up.
In the Fourth Task both simulated and hardware in the loop protocol tests have been performed and relevant results analysed. Also the EMC test campaign has been completed for the ISO118908 physical layer.
Fifth and last task has been dedicated to the study documentation finalization and closeout.