SpaceWire Router Research Articles

Applying Active Diagnosis to Space Systems by On-Board Control Procedures

The instrumentation of real systems is often designed for control purposes and control inputs are designed to achieve nominal control objectives. Hence, the available measurements may not be sufficient to isolate faults with certainty and diagnoses are ambiguous. Active diagnosis formulates a planning problem to generate a sequence of actions that, applied to the system, enforces diagnosability and allows to iteratively refine ambiguous diagnoses. This paper analyzes the requirements for applying active diagnosis to space systems and proposes ActHyDiag as an effective framework to solve this problem. It presents the results of applying ActHyDiag to a real-space case study and of implementing the generated plans in the form of on-board control procedures. The case study is a redundant SpaceWire network where up to six instruments, monitored and controlled by the on-board software hosted in the satellite management unit, are transferring science data to a mass memory unit through SpaceWire routers. Experiments have been conducted on a real physical benchmark developed by Thales Alenia Space and demonstrate the effectiveness of the plans proposed by ActHyDiag.

Spacewire router IP-core with priority adaptive routing

Design of modern spacecraft focuses on using network principles of interaction on-board equipment, in particular in network SpaceWire. Routers are an integral part of most SpaceWire networks. The paper presents an adaptive routing algorithm with a prioritization, allowing more flexibility to manage the routing process. This algorithm is designed to transmit SpaceWire packets over a redundant network. Also a method is proposed for rapid restoration of working capacity after power by saving the routing table and the router configuration in an external non-volatile memory. The proposed solutions used to create IP-core router, and then tested in the FPGA device. The results illustrate the realizability and rationality of the proposed solutions.

Design and Verification of Hardware Building Blocks for High-Speed and Fault-Tolerant In-Vehicle Networks

This paper presents the design, implementation, and validation of a FlexRay transceiver and a SpaceWire (SpW) router and interface, which constitute the main hardware building blocks of the two in-vehicle communication standards. The FlexRay protocol features data rates up to 10 Mb/s and time- and event-triggered transmissions, along with scalable fault-tolerance support, and it is expected to become the standard network for X-by-wire and active safety automotive systems. However, collision avoidance and driver-assistance applications based on camera/radar sensors require data rates up to hundreds of megabits per second as well as fault tolerance, features that can hardly be covered by current or expected automotive standards. In this scenario, a promising technology seems to be the new SpW protocol, currently used in avionics and aerospace.

Research and Design of on-Board Dynamic SpaceWire Router

Research and Design of on-Board Dynamic SpaceWire Router