CONTROL AND SIMULATION OF IMPACT IN A SOFT BODY PROTECTOR

Soft body protectors are in use in different sports, in this research we are going to focus only on the electronic body protector adopted in an Olympic Martial Art sport called Taekwondo. It is intuitive to evince that the electronic trunk protector has the aim to evaluate if a landed blow by the athlete is to be considered as a valid point or not, besides, also, giving an adequate protection to whom wears it. The purpose of this study, after a deep review of the literature concerning electronic body protectors adopted in Olympics Taekwondo competitions, is to provide a novel approach in determining the validity, or not, of a blow from the cited protector. This, was deemed necessary by the concerns raised by a few reachable articles, it must be said that not much research work has been done in this direction, moreover, since only two protectors are authorized for Olympic competitions by the World Taekwondo Federation (WTF), further possible, information may be restricted. In this work, the novel approach is developed based on inserting in the chest protect a sensorized hollow inflated deformable cylinder, together with a further sensor. The former has the aim to measure the level of force developed by a blow, while, the latter, which will be identified as a tactile sensor, has the objective to verify that the contact with an external body occurred. Stated this, the design of a control algorithm that deals with the stream of data coming from sensors is necessary. This has been developed with the use of Matlab/Simulink, addressing, not only, the problem of evaluating the magnitude of force developed by a hit, but, also, tempting, to identify the typology of technique thrown, by analysing the deformed elements. Due to the capability of the algorithm to determine the intensity of a hit, it is immediate to compare this with a fixed threshold, defined properly on base of the weight category, and, to determine the validity of a blow. Together with this, a modelling procedure of the deformable elements is carried out, where, on the basis of a fixed constraint on the maximum deformation displacement, the values of stiffness and damping are determined. At last, an analysis of the force transmissibility thought a defined zone of the protector is carried out. Concluding, we can identify in this study a good starting point to develop new methodologies to be adopted in the domain of electronic body protectors, and to maintain, this is the case of Taekwondo, that transparency in scoring required to keep the sport attractive and spectacular.