Firmware upgrade method for underground precise positioning system terminal based on UWB + LoRa

To address the dual challenges of upgrade efficiency and service reliability in wireless firmware updates for underground coal mine positioning systems, this study proposes a dual-mode redundant upgrade architecture based on coordinated transmission of ultra-wideband (UWB) and long range low-power wireless communication technology (LoRa). The architecture organically integrates centimeter-level high-precision positioning capability of UWB with wide-area communication coverage of LoRa, thereby establishing a heterogeneous network system with spatial self-adaptation. In communication strategy design, a dynamic dual-mode coordination mechanism is developed. In sparsely distributed terminal areas, the system employs UWB technology for time-division multiplexing of positioning signals and firmware upgrade channels, which simultaneously meets precise positioning requirements and enables point-to-point firmware transmission; in terminal-dense areas, a dual-mode division-of-labor mechanism is enabled, while UWB continuously provides real-time positioning services, independent channels of LoRa are used for parallel broadcast-style firmware distribution, thereby significantly enhancing the efficiency of multi-terminal upgrades. To ensure secure operation in complex underground environments, a triple-layer protection system is implemented. First, a hierarchical key management system combining RSA asymmetric encryption and AES symmetric encryption establishes peer-to-peer encryption for firmware transmission, effectively preventing data leakage and tampering. Second, an adaptive firmware acquisition mechanism based on spatial distribution characteristics enables terminals in sparse areas to actively initiate firmware requests while base stations proactively broadcast upgrade packages in dense areas, incorporating firmware breakpoint resume functionality to enhance transmission reliability. Third, a dual-partition firmware upgrade strategy performs CRC-32 cyclic redundancy checks and SHA-256 Hash verification at the Bootloader layer, ensuring automatic rollback to stable backup partition versions upon upgrade failures. Experimental results demonstrate that the system maintains the maximum positioning error below 30 cm regardless of whether in the sparse area or the dense area of the terminals, achieving 100% firmware upgrade success rate. This fully validates the comprehensive advantages of the dual-mode redundant architecture in precision positioning, upgrade efficiency, and operational reliability.