Yacht performance monitoring in real sailing conditions

In this paper a multi-method approach is used to setup and validate a monitoring system applied to a small sailing boat during real sailing conditions. This monitoring system is able to transform the data coming from some typical devices installed on board into information about the deformed state of the boat. GPS, Wind Data Logger and cameras have been installed on the boat to measure its route and speed, the apparent wind velocity and direction and the positions of the crew members. These data are processed to determine the equilibrium of the boat and estimate the loads applied on it. Then, a CAD/FEM model calculates the effects of these loads on the boat shape. The resulting deformed model is compared with measurements of local strains obtained with Electrical Resistance strain gauges applied on the hull and on reinforcements of the boat. Onboard measuring devices are real-time monitored with a home-made software while the numerical prediction of the global boat deformation is obtained a posteriori once FEM computation is achieved. A test at sea has been performed to check the efficiency of the system: data computed with the proposed procedure have been compared with those coming from the field test