The design of dual-channel proximity sensing electronic unit on civil aircraft

The Proximity Sensing Electronic Unit is the core of the Door Signal System, which processes and logically handles the signals from proximity sensors installed at locations such as passenger doors, service doors, etc. It transmits information such as cabin door status through the ARINC429 (Aeronautical Radio Inc. 429 Specification) bus to the avionics network for interaction with various systems. This paper introduces the hardware architecture and design of the dual-channel Proximity Sensing Electronic Unit. The redundant design of the dual-channel architecture and ARINC429 communication module can enhance the effectiveness and availability of data. With Isograph's Reliability Workbench software, the loss of passenger door/service door status indication is treated as a top event for fault tree analysis to verify its compliance with the probability requirements of the system functional hazard assessment report.