Sports Auxiliary Coaching System Based On Hybrid Motion Capture Technology

As the number of people participating physical exercises in China increases year by year,the shortage of sports coach resources becomes more and more severe.Especially in the central and western regions,basic physical education has not yet been fully popularized.As a means of digitally recording the position and posture of moving objects,motion capture provides a technical foundation for the digitization of sports.Digital sports training based on motion capture technology is expected to reduce the experience dependence on coaches during the training process and popularize the basic physical education.This work studies the auxiliary coaching systems applicable to most sports.The main innovations of this work are as follows:Based on the refinement of traditional sports training patterns,this paper first proposes a general knowledge-based sports auxiliary coaching framework.The framework mainly includes four modules: domain knowledge,trainees,performance evaluation,and controller.The domain knowledge module digitalizes the knowledge of the sport such as practice contents,improvement instructions,and skill indicators.The trainee module stores the trainee's action response to the practice content and improvement instructions.The performance evaluation module obtains the trainee's original motion data from the motion capture device and further calculates the sports features.Based on the performance evaluation results,the controller decides to give the trainee improvement instructions or to practice new content.The system will operate until the trainee reaches the predefined goal.Then the implementation of the general coaching framework in specific sports is studied,that is,the expression of domain knowledge and the construction of a motion capture system.This paper takes table tennis as an example to describe the practice content,sports features,and skill level in the framework in detail,and determines the motion capture devices suitable for table tennis and features calculation methods.At the same time,in order to further improve the accuracy of the inertial motion capture system to restore the trainee's posture,this work improves the original inertial motion capture system from two aspects of contact judgment and posture correction based on contact position constraints.The simulation results show that the corrected human posture has better smoothness of movement.Finally,a demonstration of the application of the general framework in the field of table tennis has been carried out.This work builds a table tennis auxiliary coaching system based on hybrid motion capture technology and invites table tennis players with different levels to participate in the experiment.The experiment shows that for different trainees under the same set of practice content,the trainee level(return-ball quality and standard of movement)calculated by the system is consistent with the actual situation.The experiment result has preliminarily verified the effectiveness of the system and laid the foundation for further research on high-precision,interactive sports auxiliary coaching systems in the future.