Tennis Sports Intelligent Monitoring System Based On Flexible Pressure Sensing Array And Inertial Sensing Unit

As an auxiliary tool,the intelligent monitoring system can carry out data analysis and processing on the typical movements of athletes to improve their competitive level.Among them,the analysis of hitting movements and the study of force law are of great significance to improve the level of tennis skills.The current tennis monitoring system usually uses a high-speed camera to record the hitting action,which has disadvantages such as strong subjectivity and single data type.With the development of portable sensing technology,inertial measurement units（IMU）and flexible pressure sensors have been widely used in motion monitoring to collect acceleration and pressure data,but there are limited application scenarios and a single type of data collection（only acceleration or pressure data）and other shortcomings.Therefore,how to integrate multiple sensors to collect multiple types of data and realize the precise analysis of hitting action and force law has become an urgent need in the field of tennis.In order to solve the above problems,this paper develops an intelligent monitoring system for tennis sports that integrates arrayed flexible piezoresistive sensors and IMU（inertial measurement unit）,which can analyze the standardization of players’hitting movements and the correctness of force delivery methods.The flexible piezoresistive sensor uses a new carbon-based material Ti₃C₂ as the conductive material of the functional layer,melamine sponge as the substrate of the functional layer,and uses screen printing technology to make interdigital electrodes.The sensor has the advantages of high sensitivity(5.35 k Pa^-1),wide measurement range（1.1～266 k Pa）,short response/recovery time（300 ms/180 ms）,high stability（>5000 cycle loading）,etc.The IMU can collect three-axis acceleration data using existing modules.It is light in weight,small in size,easy to use,has a delay of 30 ms,and a real-time output frequency of up to 60 Hz,which fully meets the monitoring needs of tennis sports.The tennis sports intelligent monitoring system proposed in this paper distributes array flexible sensors on the surface of the grip of the tennis racket to monitor the pressure changes of the key points of the hand in real time during the tennis hitting process,so as to judge the correctness of the power delivery method.Fix the IMU on the top of the racket grip to monitor the acceleration changes of the racket during the hitting process in real time,so as to distinguish different stages of hitting the ball and judge the standardization of the hitting action.The system combines an array of flexible sensors with an IMU to monitor tennis players of different technical levels,draw rules and use them to judge the technical level of the players.Through the artificial intelligence algorithm and key point pressure data,it can successfully identify representative movements in tennis,with a recognition rate as high as 98.4%.The proposed intelligent monitoring system for tennis sports combines flexible sensors with rigid sensors,providing a new solution for intelligent monitoring of sports.