Utveckling av mätmetod för att bestämma glidfriktion vid längdskidåkning

Abstract

Cross-country skiing is a major sport where many different parameters influence an athlete’s performance. One such parameter is the friction between the ski and the snow. Skiers have been trying to reduce this friction ever since the sport began. Today, this is primarily achieved through various surface treatment methods, including both waxing and base structuring. However, one ongoing challenge is to measure the effectiveness of these methods in a quantitative and scientific manner. The aim of this project was to develop a method for measuring the coefficient of friction in cross-country skiing in a way that is both scientifical and user-friendly. A motion equation was developed to describe the relationship governing the coefficient of friction in skiing. This was followed by a literature review of existing solutions. Based on the insights from this review, a development process was carried out to create a measurement technique and corresponding test methods to validate it. The project resulted in a measurement system consisting of an IMU, a custom software solution, and either magnets or photocells. The method was tested through glide tests indoor in the Skidome ski facility in Gothenburg. Each test involved a 15 meter long glide phase at speeds of up to 6 m/s. The results demonstrated that the technique was capable of detecting differences in friction with a precision better than ±0.005. The conclusion of the project is that the equipment provided useful data that could be of value to recreational skiers and in training environments. Further development of the software and an upgraded IMU could potentially provide sufficient precision to compare different types of glide wax at an elite level.