基于MEMS传感器的无线传感网络节点的硬件设计

摘要

In order to solve the problems of monitoring the healthy and safety of the buildings,the micro-electro-mechanical system (MEMS) technology and wireless sensor network technology were investigated. The structure and working principle of the accelerometer with the actuators droved by Lorentz force for increasing the initial sensing capacitance were introduced. Then the capacitance detection circuit was designed. ANSYS simulation software was used to evaluate the performance and Multisim was used to simulate the detecting circuit. The results show that the sensor could detect the three-dimensional acceleration signal;its static sensitivity can be 0.558 jJim/g;the dynamic measurement range is 10 g; and the output is in accord with the simulation result. The hardware of the wireless sensor network node was designed which was constructed by MSP430F1611 as MCU,chip CC2430 was used to realize the wireless transceiver and some interface circuits around to monitor the displacement signal. With the inner temperature sensor to test,the results show that the nodes can realize the monitoring and meet the system design requirements.%为了解决对建筑物的结构健康安全监测进行在线监测的问题,采用微机电系统(MEMS)技术和无线传感器网络技术相结合的方法,提出了一种基于磁驱动增大检测电流的新型电容式加速度传感器结构,介绍了其工作原理,并设计了该传感器的电容检测电路,在ANSYS仿真软件上对传感器性能进行了评价,在Multisim上对检测电路进行了模拟仿真；仿真结果表明,该传感器可以检测三维加速度信号,静态灵敏度可达0.558 μm/g,动态测量范围为10 g,电路实际输出与仿真结果相符,符合要求；在节点整体方案设计中以低功耗的MSP430F1611作为控制MCU,以CC2430芯片实现无线收发,配合周围接口电路实现了位移信号的监测功能；采用片内温度传感器对节点进行了测试.测试结果表明,该节点能够完成监测,满足设计要求.