低功耗机械振动无线传感器网络节点结构设计

Low power node architecture design for mechanical vibration wireless sensor networks

针对目前机械振动无线传感器网络节点能耗高的问题,提出一种低功耗节点硬件结构设计方法。采用低功耗、高灵敏度MEMS加速度传感器采集机械振动信号,简化电源及调理电路;采用通带可调的开关电容低通滤波器,实现低功耗动态抗混叠滤波;在充分考虑存储速度的前提下,采用低读写电流的外部Flash存储芯片实现连续、高速数字信号流的存储;采用片上系统级芯片作为整体控制核心,集采集、存储、无线传输于一体,在保证机械振动信号采集性能的同时,极大的减小节点体积与功耗。对比实验结果表明基于该低功耗硬件结构的机械振动无线传感器网络节点具有较低的功耗水平。

In view of the high energy consumption at the nodes of current mechanical vibration wireless sensor networks , a low power node architecture design was proposed. A low power, high sensitivity MEMS accelerometer was adopted to pick up mechanical vibration signals, which simplifies the power and conditioning circuits; a switched capacitor low-pass filter with adjustable passband was used to realize the dynamic anti-aliasing; a flash storage chip with low operating current was applied to store the continuous and high-rate digital signal streams, which takes into full consideration of the storage speed. A SOC was adopted to act as a whole control core, which controls the acquisition, storage and wireless transmission process. Besides ensuring the mechanical vibration signal acquisition performance, the SOC greatly reduces the nodal size and energy consumption. A comparison between the energy consumption of the proposed low power architecture and a typical dual-core-processor architecture was conducted, and the results indicate that the node based on the proposed low power architecture is of satisfactory low energy consumption performance.