Design And Research On The Rapid Measurement System Of Friction Resistance In Freestyle Skiing Ground

The freestyle skiing aerial skill movement is one of the most popular sports in the Winter Olympics.In this sport,the final achievement of athlete is directly related to the launching speed.In the process of skiing,various environmental resistances,mainly the friction resistance of snow surface,have a great influence on the launching speed.Before completing the action,athletes need to make a preliminary estimate of these environmental resistances in order to take some appropriate technical adjustments.However,the estimation of resistance by athletes and coaches is completely based on their own experience,and there is no quantitative data for reference.In order to solve this problem and respond to the national call of "Technology Winter Olympics" major project,this paper developed a set of rapid measurement system for the frictional resistance state of freestyle skiing ground,and it could provide the data reference for athletes to take an appropriate technical adjustment before the competition.The main research contents of this paper are as follows:(1)By consulting a large number relevant literatures,the principle and the method of friction resistance measurement of snow were analyzed.And then the measurement schemes in the measurement system of this study were analyzed for the application scenarios.And the design ideas of this study were proposed according to the functional requirements such as response time,operational stability and environmental adaptability.(2)The overall structure of friction resistance measuring instrument was designed and built.After analyzing the measurement principle,SolidWorks software was used to design the structure of the whole machine and its parts,and ANSYS software was used for the modal analysis of the whole machine to verify the rationality of its structure.(3)For the measurement process of friction resistance measuring instrument,its control system was built.After analyzing motor synchronization control theory,PID series synchronization controller of DC motor was designed.Then asynchronous control of stepping motor and synchronous control of DC motor were realized by using Arduino.(4)A data acquisition and processing system was designed and built.According to the principle of friction resistance measuring instrument,the solution method of friction resistance was analyzed.And the data acquisition of photoelectric encoder,inclination sensor and other sensors was realized by Arduino.And the power module of the whole measuring system was completed.Lab VIEW was used to design the upper computer interface of the acquisition system to realize the data collection,display and management.(5)After debugging the friction resistance measuring instrument,a series of experiments had been done.By using MSA correlation theory,the stability of the measurement process and the correlation with the standard measurement equipment were analyzed.The experimental results showed that the measurement system was reasonable,stable and reliable,and met the functional requirements.