2017, Volume 13, Issue 1

Testing the prototype of the educational judo trainer with the use of augmented-reality technology



Kazimierz Witkowski1, Janusz Sobecki2, Roman Maciej Kalina3, Jarosław Maśliński1, Wojciech Cieśliński1, Cezary Sielużycki2, Paweł Piepiora1

1Department of Martial Arts, University School of Physical Education in Wrocław, Poland
2Faculty of Computer Science and Management, Departament of Computer Science, Wrocław University of Technology, Poland
3Department of Combat Sports, Gdansk University of Physical Education and Sport, Poland


Author for correspondence: Wojciech Cieśliński; Department of Martial Arts, University School of Physical Education in Wrocław, Poland; email: wojciechbcieslinski@gmail.com


Abstract

Background and Study Aim: Preliminary results of unique studies using virtual reality technology reveal that accumulated motor experience (fixed movement habits) in long-term judo training (judo ichidai) provide surprising adaptive effects (in positive sense). The main premise of this stage of research is that in judo as an Olympic sport discipline, the division into weight categories is a major factor in the somatic differentiation of athletes. Therefore, convergence in the somatic sense, the avatar of the athlete and the avatar of the master (i.e., coach) is a condition of comparing the throw technique by overlaying (in the recostructing time) the avatars over themselves. The aim of this work is implementation of the augmented-reality (AR) technology capabilities into the specifics of teaching judo throwing techniques precisely because of the somatic differentiation and motor skills of novices and masters.

Material and Methods: The key element is to determine joint positions and then detect them by MS Kinect while performing a specific throw. Practically “the prototype of educational judo trainer (EJD)” is entered in the following algorithm: (1) measurement position of joints; (2) recording a pattern, (3) playing a recorded pattern or training; (4) scaling and synchronization; (5) training with the pattern; (6) determination of absolute error and “indulgent”. Generating judo throws in 3D technology enables to perform the following functions: loading a judo throw; watching a judo throw in 3D; change the position of the observation point; application by selecting Real Time Animation.exe file. Experimental usage based on demonstrations of the three-time world judo champion in open and heavy category compared to the judo throw technique used by judo athletes of the different technical levels, but also by the karate world champion, who passed a short course of techniques previously unknown to him in judo.

Results: Alternative performance of throw at 3D animation character (the master and novice's multi-colored avatars are next to each other or superimposed) gives the possibility of choice by the novice of the visual way of registering the new motor activity. There are people who accept alternate use of both methods (this variant is preferred by athletes with a very high level of combat sports mastery but not by previously trained judo).

Conclusions: Avatars of pattern and diagnosed adept of judo should have different colours of judogi (white and blue). The prospect of displaying the EJD interface not only on the large screen, but also on the viewfinder glasses presents a real challenge for optimal use of AR technology in judo training. This applies to areas of diagnosis, correction, and adaptive effects calculated to prevent excessive use of the body, for example by eliminating the excessive number of repetitions of throws or its elements (uchi komi).


Key words: effort safety, judo ichidai, motor safety, optimize of workout, uchi komi