The Design And Implementation Of Cardiorespiratory Fitness Test System Based On Constant Power Exercise Bike

Cardiorespiratory fitness characterizes the ability of the body to continue physical activities,which reflects the ability of cardio pulmonary function of the human body in a certain exercise intensity,is considered to be the one of the most important indexes in the health fitness evaluation system.For the public,a good cardiorespiratory fitness level can greatly prevent the occurrence of many diseases.However,the traditional cardiorespiratory fitness testing equipment is not widely used for its professional,high risk,high price and other factors,which leads to the current study on cardiopulmonary fitness of public health and popularity level can't meet the urgent needs of the application.In this thesis,we carried out the study of cardiorespiratory fitness assessment system based on constant power exercise bike,the main work is as follows:(1)The hardware design of intelligent constant power exercise bike.We designed a new type of electronmagnetical device based on the transformation of traditional exercise bike,which use coil winding wheel instead of magnet wheel through the PWM principle to achieve the rapid adjustment of resistance,the collection of speed,pressure and heart rate,wired and wireless data communication design.(2)The software design of intelligent constant power exercise bike.The software design includes slave software and host software,the slave software mainly includes power calculation and constant power control,host software includes user information management,regular exercise and cardiorespiratory fitness test,heart rate and exercise data display,test report display and upload,as well as good human-computer interaction,design of communication protocol between host computer and slave computer.(3)Design and verification of cardiopulmonary fitness test program based on constant power exercise bike.The maximal oxygen uptake(V02max)value is the criteria for assessing cardiorespiratory fitness,the measurement method of V02max is divided into direct measurement and indirect measurement,however,the direct measurement method is difficult to be popularized in the mass for its high price,complicated measuring process and high risk,therefore,this thesis chooses two commonly used indirect measurement methods-YMCA method and Fox method,based on the test platform of constant power exercise bike,according to the two methods,calculate the heart rate of the tester in a certain period of time and intensity,and predict the maximum oxygen uptake test value with corresponding formula,and evaluate the tester cardiorespiratory fitness.In order to verify the accuracy of the equipment test results in the two kinds of test scenarios,this thesis selects the MORNK power cycle to do experimental comparison which regards as gold standard of cardiorespiratory fitness measurement,found that two devices test results are highly correlated,indicated that the cardiorespiratory fitness evaluation system based on constant power exercise bike has good scientific and effectiveness.The main innovation points of this thesis include:1.Design and implementation of a new type of resistance regulation,adjust the output voltage by PWM principle,and then adjust the magnetic field strength,to achieve rapid adjustment of resistance,compared with the traditional damping exercise bike,the resistance control method has the advantages of wide range of resistance regulation,higher control precision and faster regulation speed,provides the prerequisites for the constant power control system.2.To achieve a constant power output during exercise,using the PID control principle,and according to the resistance control mode mentioned above,the size of the resistance is adjusted in real time so that the output power of the system can achieve and maintain the set target power,and ensure the constant power output of the test equipment in cardiorespiratory fitness test.3.Two kinds of simple and effective cardiorespiratory fitness test programs were used on the platform,provides a practical solution of the cardiorespiratory fitness test for the general population,at the same time,solves the high price of foreign testing equipment,and fills the blank of domestic power vehicle test equipment.