Development and validation of an instrumented monoski for kinematic and kinetic data collection

OBJECTIVES: The main purpose of this thesis is to provide mechanical and electronic tools to study the monoski complex system in both indoor and outdoor environment. In order to collect kinematic and kinetic data, an Instrumented Monoski needs to be developed, which can be used in indoor and outdoor environment. In particular, ground reaction forces, the variation of damper stroke and speed, the seat and body vibrations and inclination are to be measured. To acquire the kinematics of the frame of the monoski and of the skier it is necessary to identify the best sensors. Moreover other objectives of the current research are: the improvement to the Multicomponent Load Cell by integrating the amplification stage, its calibration using an innovative method called Neural Networks. MATERIALS AND METHODS: An extensive literature review was conducted to identify articles focusing on monoskis and dissertations with the same research objective. The research then focused on different methods for the calibration of load cells. The Neural Networks, which is part of the Deep Learning Toolbox of MATLAB, was used for the purpose of the research. To acquire the kinematics of the frame of the monoski and of the skier it is necessary to identify the best sensors. The ground reaction forces are measured using the Multicomponent load cell that was developed, the damper stroke and speed has been measured using a linear potentiometer placed in parallel to the shock absorber, the seat and body vibrations and inclination were acquired using triaxial accelerometers and a gyroscope. Moreover an investigation on the dynamic behaviour and vibrations of the monoski was performed. This research work was carried out mainly in the Sports Tech Research Centre in Östersund at the Mid Sweden University (SWE) from 22th of February to 13th of June. Further validation tests were performed in the final phase of investigation at the Department of Industrial Engineering at the University of Padua (ITA) from the end of August to the beginning of October 2022. RESULTS: The outcomes of indoor tests show that the foot load cell is able to correctly measure static and dynamic loads with high accuracy. The whole measurement systems perfectly provide reliable data, which confirms the validity of the methods and instruments used. CONCLUSIONS: The aim of this thesis to collect data for the design and development of monoskis was achieved, and reliable data are now available for further investigations. A limitation of this study is that data were collected indoor therefore outdoor testing would be necessary to further confirm the results achieved. It is hoped that this work will serve as reference for many future developments: the Instrumented Monoski can soon be used for tests on ski slopes, opening the way for the design of an innovative, cost-effective and high-performance monoski. This interesting work will lead to the development of a user friendly and safe monoski to make this sport more accessible to individuals with disabilities.