Design And Initial Validation Of A Wireless Control System For Cantilever Based On WSN

At present, cantilever structures used widely in civil structure would generate continuous vibration by external force due to their low damping characteristic, which leads to a serious impact on the working performance and service time of the cantilever. Therefore, it is very important to control the vibration of these structures. The active vibration control is widely used for its high precision and strong adaptive ability. Piezoelectric materials can achieve cheap, reliable braking and sensing method which is lossless of the structure, therefore they have a broad application space. Nowadays, there are many researches using piezoelectric materials in the structural vibration control. In traditional sensor applications, information exchanges with the monitoring center or a computer system through wires, so that it’s difficult to maintain and complex to design.Based on the factors above, a wireless control system is designed and validated through preliminary tests. The system not only can effectively control the vibration of cantilever, and also have lots of advantage. This work includes:First, get the feature of piezoelectric material through experiment. Second, design the algorithm of the system based on the theory of the structure vibration control. Third, make a model to analysis the cantilever structure, and build the wireless cantilever control system. The system consists of a cantilever, PVDF as sensor, signal conditioning circuit, A/D acquisition board, control arithmetic unit, D/A output board, power amplifier, piezoelectric bimorph as actuator. DSP chip is used as the control arithmetic unit and PD control algorithm is embedded in it. PVDF collects the parameters of vibration, sends them to the SCM after A/D conversion. SCM passes the data to the DSP through wireless technology, and DSP calculates and outputs the control values according to the control algorithm. The output signal is amplified to drive the piezoelectric bimorph. The structural vibration duration reduces to1/5of the uncontrolled case, which verifies the feasibility of the system.Last, there is an optimization solution focus on the delay of the wireless system. Related simulation and test are performed. The wireless control system of this thesis is simple and efficient. Besides, it is applicable and could be used as a reference for actual projects.