基于LoRa的低功耗瓦斯浓度分布式监测系统设计

Design of low-power distributed gas concentration monitoring system based on LoRa

针对催化燃烧式甲烷传感器功耗较高及有线瓦斯浓度监测系统安装成本高、扩展性和灵活性差、维护工作量大等问题,设计了基于LoRa的低功耗瓦斯浓度分布式监测系统,详细介绍了瓦斯浓度采集节点与LoRa智能网关的软硬件设计。瓦斯浓度采集节点采用STM32L151超低功耗系列处理器,通过电源管理模块将系统电源分为可控的3个部分,并通过功耗控制策略降低功耗:①单片机核心系统采用低功耗模式;②MJC4/2.8J甲烷检测用载体催化元件采用动态通电方式,以降低平均电流;③采集节点中除单片机核心系统外的其他模块按需供电。LoRa智能网关利用嵌入式实时操作系统μC/OS-II进行任务调度,使网关性能达到最优,提高CPU的利用率。测试结果表明,瓦斯浓度采集节点具有较好的数据传输性能,功耗控制策略可有效降低采集节点的平均电流,从而延长电池使用时间,降低系统维护工作量。

Catalytic combustion methane sensors are high power consumption.The wired gas concentration monitoring system has high installation cost,poor scalability and flexibility and heavy maintenance workload.In order to solve the above problems,a low-power distributed gas concentration monitoring system based on LoRa is designed.Moreover,the software and hardware design of gas concentration collection nodes and LoRa intelligent gateway are discussed in details.The gas concentration collection nodes use the STM32L151 ultra-low-power series processor.The system power supply is divided into three controllable parts through the power management module,and the power consumption is reduced through the power control strategy.①The microcontroller core system adopts a low-power mode.②MJC4/2.8J methane detection carrier catalytic element adopts dynamic energization to reduce the average current.③The modules in the collection nodes other than the microcontroller core system are powered on demand.The LoRa intelligent gateway uses the embedded real-time operating systemμC/OS-II for task scheduling to optimize the performance of the gateway and improve CPU utilization.The test results show that the gas concentration collection nodes have good data transmission performance and the power consumption control strategy can reduce the average current of the collection nodes effectively,thus extending the battery life and reducing the system maintenance workload.