Windsurf Ergometer for Sail Pumping Analysis and Mechanical Power Measurement

Sail pumping in windsurfing is a manoeuvre in which the surfer pulls and pushes the sail rhythmically so that it acts as a wing, thus providing the board with additional propulsion especially in weak and moderate winds. In windsurfing, sail pumping is considered particularly effective at low wind velocities while at higher wind speeds this action loses its efficacy or physically it becomes too demanding. The physiological effects of sail pumping have been investigated in literature. For this purpose, on-water measurements have been carried out during actual sailing using a portable metabolimeter and ashore measurements have been performed using a cycle ergometer or windsurfing simulator. The results have shown that windsurfing is a high-energy expenditure sport which shows high demands of the aerobic metabolism of athletes especially under weak wind conditions. Both cycle ergometer and windsurfing simulator were used in laboratory conditions which were not the same as on-water ones.In this paper we present an embedded system designed in order to quantify the power developed by a windsurfer during sail pumping. This device measures both the applied force and the displacement of its point of application by the means of extensometric sensors and inertial module unit placed on the rig. Other sensors have been attached on the athlete for biomechanical and physiological measurements. Preliminary results are presented and discussed in this work.