Wearable Snow Friction Harvester Based on Traditional Skis

The frictional resistance on snow surface has an impact on athletes' score ranking in competitive skiing. To reduce the drag force and improve the athlete performance, the studies on snow tribology and lubricating materials are desired urgently. Whereas, the friction on snow is influenced by a variety of factors including temperature, humidity and snow conditions, etc., and the precise friction test on snow surface, especially for the real skiing condition, is a challenging. This study presented a wearable snow friction in-situ measurement device for the traditional skis. The measurement device consisted of two parts, including friction signal acquisition device between skis and ski boots, and the data acquisition system arranged in the backpack carried by the tester. In the friction signal collecting device on the traditional skis, four three-component sensors were logically organized on the traditional skis. The force signals of the component were tracked, gathered, and saved via a wired connection in conjunction with a data acquisition card. The change in the force signal was fed back in real time via the terminal portable computer. In the laboratory test, the apparatus could give a stable force signal output that provided accurate friction coefficient test results and distinguished different actions. In the simulated ski field test, the snow friction in-situ measurement device was tested in a simulated indoor snow slope, it could correctly assess the friction force signal while skiing, and could effectively evaluate the lubricating on performance and anti-wear resistance feature of various snow waxes. By analyzing the specific force signal, and the device also could monitor the traditional technical movements of free style alpine skiing including the typical plough pizza braking or turning movements. Based on the high precision and high sensitivity of force signals, the apparatus provided a feasible solution for the evaluation and observation of an athlete's force-applying motions in daily training.