Information architecture technologies for realization of panel extension satellite (PETSAT)
- Paper number
IAC-06-B5.7.06
- Author
Mr. Kanichi Koyama, Astro-Technology SOHLA, Japan
- Coauthor
Mr. Takanori Okada, Astro-Technology SOHLA, Japan
- Coauthor
Ms. Chisato Kobayashi, Astro-Technology SOHLA, Japan
- Coauthor
Prof. Shinichi Nakasuka, University of Tokyo, Japan
- Year
2006
- Abstract
This paper proposes realization methodology information architecture (I.A) of a microsatellite, named PETSAT. PETSAT is made of several “Functional Panels” each of which has a special dedicated function. And PETSAT has various configurations by connecting these panels just as cartridges. Communication between panels is essential for PETSAT. The information line should be very reliable and should have enough communication capacity to deal with many data. In addition to these requirements, panels should have cold plug-in connectivity to realize flexible configurations of PETSAT. Each panel should have a certain level microprocessor for controlling this information traffic as well as managing the information flow inside the panel. These microprocessors are adopted as panel controller board (PC board) in all panels. PC board adopted two major communication bus interfaces (CAN, IIC) to realize facilities mentioned above. Of these two bus interfaces, CAN bus is used as outside bus interfaces to keep high speed communication and connectivity between various panels. PC board applies the two major feature of HCAN protocol. The first one is the automatic collision evasion function to solve the communication collision occurred between panels. The second one is arbitrary judging feature to keep connectivity of panels. By using HCAN protocol, collision problem has almost solved in BBM, Network test board of PETSAT. And, to connect these panels like cartridges, PC board utilizes arbitrary bit and Mailboxes defined in HCAN protocol (HCAN is trademark of Hitachi RENESAS Corp.). PC board has each self identifier (SID) inside of EEPROM as arbitrary bit. And when panels are connected as configuration of PETSAT and boot up each PC board, PC board read the information written in EEPROM for distinguish each other. Thus, panels have no serious problem related to collision in the process of communications and connectivity. In addition to utilization of HCAN protocol, IIC is also used as bus interfaces. IIC has also enough capacity of communications between PC board and inner various components of “Functional Panels”. IIC has also useful feature to realize PETSAT I.A. The first one is multi-mastered communication feature. And the second one is automatic arbitrary solving feature. PC board utilizes two features to solve cold plug-in connectivity and conflict problem of communication. As result of these I/F adoption, I.A of PETSAT has realized high connectivity and high-durability for collision of communications.
- Abstract document