**4.3 FDIR scheme**

The software autonomously isolates the failure and rebuilds the system at the appropriate time according to the following FDIR scheme:


## **4.4 FDIR processing requirements for satellites in orbit**

The FDIR requirements for each phase of the satellite are as follows:


iii.On-orbit phase: allows failure detection and recovery of level 0 to level 4 failures.

#### **4.5 FDIR processing**

The processing flow of FDIR mainly includes four parts:


#### **5. Impacts on next-generation avionics system**

The intelligent avionics system adopts a system engineering method using modular and open design to uniformly design the information processing, control and management processes, hardware, and software, which is to realize the optimization of information and resource sharing. Based on the onboard computer and high-speed bus such as SpaceWire data bus, a set of information fusion systems and mechanisms is established. The system is a menu-style, modular, and extensible open service platform, which achieves a high degree of integration of various onboard software and hardware resources and can meet the requirements for different tasks.

The intelligent avionics system adopts the design concept of a modular menu system architecture to meet the needs of real-time, reconfigurable, autonomous planning, and intelligence of the system. With the SMU as the 1553B and SpaceWire bus controller for data rate less than 10 Mbps/for data rate more than 10 Mbps, respectively, and the ISU as the remote terminal, a distributed, master-slave, and menu-based satellite networks are constructed.

Satellites are designed with a network layout, which can design different menu network nodes on the bus network. After the payload capacity is strengthened, the network node can increase the corresponding payload processing unit. The SMU is used as the main processing computer to perform the main control of satellite services to form a master-slave network structure. The high-performance onboard processor enables the intelligent avionics systems with high-performance computing capabilities, which not only meets the data processing requirements but also lays the foundation for satellite intelligence. The intelligent avionics system adopts partition protection measures. Through the design of space protection, time protection, and partition communication, it provides reliable functional entities (such as

#### *Design of Intelligent and Open Avionics System Onboard DOI: http://dx.doi.org/10.5772/intechopen.93141*

software modules or hardware modules) that share resources. Partition protection avoids the impact of other partitions under abnormal conditions such as single partition failure or malicious access. At the same time, the intelligent avionics system is equipped with real-time multitask distributed system software, which can realize the dynamic reconstruction of functions and tasks. For example, when a node fails or needs a functional reorganization, some tasks on that node will be migrated to other nodes. Or, the resource occupation rate of a node is too high, and some tasks on this node will be migrated to other relatively idle nodes for execution. This design can improve the failure tolerance of the intra-satellite network and achieve efficient resource allocation and scheduling. All information is collected into the SMU for comprehensive analysis and processing through the 1553B/SpaceWire bus network. For example, in the process of autonomous energy management, it is found that the battery discharge depth reaches 80%. If the control sub-system is still in the mode of pointing to the ground, it will seriously affect the safety of the satellite. At this time, the instructions should be sent in time to orient the satellite to the sun to ensure the safety of the satellite. The SMU can be fully applied to the satellite's autonomous information fusion processing, ensuring that the satellite can still guarantee normal communication services in the event of a major failure, and energy security in emergency situations.
