Deflection and inclination measuring system for floating dock based on wireless networks

When going in or out of a dock, the self weight of the ship may cause the deflection of the pontoon deck and/or inclination of a floating dock. This paper investigates the measurements of the deflection and inclination of a floating dock within a wireless network. A deflection measurement model is constructed on the basis of the multi-points liquid levels in the connected pipes. The water levels at different points are measured by the pressure transmitters connected to the connection pipes along the longitudinal direction of the floating dock. The inclination is measured by 4 pneumercators installed on 4 corners of the floating dock. The measured data are transmitted to a server with a wireless sensor network. With the proposed model, the deflection and inclination calculation methods are analyzed and presented. The experimental results show that the accuracy of the deflection (hog or sag) can reach 95% and the error for the inclination measurement (heel or trim angle) is less than 8%. It is verified that the measuring system in the wireless sensor network supports the proposed deflection model and data collision avoiding algorithm. The measuring system could provide the required information during the operation of the floating dock.