The Design Of Full-range Wireless Tilt Sensor

Tilt measurement has been widely applied in many practical engineering such asgeological drilling mapping and engineering survey, dam displacement and bridgedeformation controlling, seismic crustal change monitoring, machine installation andelectronic balancing, aircraft control system, equipment platform control system andvarious level measurements. Nowadays, the network technology has been widelyused in industry, agriculture, national defense and scientific research. As a result, thewireless sensor network technology is highly emphasized by various researchers inthe field of network study. It is also a trend for future industrial communication. Thispaper focuses on the issues of hardware design of the sensor nodes, sensor dataacquisition and processing and the constitution of the cluster tree networks. Theachievements that have been obtained are as follows:Firstly, the working principles of the tilt sensor measurement are discussed.Considering the limitation range of the acceleration sensor tilt measurement, thispaper proposes a solution of installing coaxial and orthogonal dual-axis accelerationsensors to measure tilt by the quadrant discriminant method.Secondly, a hardware system consisting of tilt measurement module, signalprocessing module and RF module is designed. Based on the system, the key issuessuch as sensor filtering, the pulse width resistor optimization, the maximumtransmission power transferring and avoiding echo loss are discussed. The hardwareof the full-range wireless tilt sensor is designed and accomplished.Thirdly, the software requirements of full-range wireless tilt sensor network areanalyzed. Then the software design of the CC2530hardware support moduleprogram, the accelerating sensor module program and the wireless communicationprotocol module based on IAR Embedded Workbench V7.51A for8051integrateddevelopment environment is completed and debugged.Fourthly, the tilt calibration experiment is conducted, and the least squares method is used to build the sensor input-output modeling. Sensor thermal zero pointdrift and sensitivity drift experiments are carried out, and two methods are used tomodeling and compensating the temperature characteristics of the sensor. Thewireless performance including the sensitivity of the sensor nodes, the antenna gainand the node transmission power are debugged. A wireless network is composed ofthree wireless tilt sensor nodes and the transmission performance of this network isdebugged to verify that the wireless tilt sensor nodes are stable and reliable.Finally, the research work is summarized. The study of the full range of wirelesstilt sensor is prospected based on that.