# User Assessment of a Customized Taekwondo Athlete Performance Cyber-Physical System
## 2 Methodology
### The SPERTA System
The equipment utilized by athletes comprises a compact board built on ESP8266 with Wi-Fi capabilities, along with an accelerometer and gyroscope module, a battery, and a power management module (Figure 2). To ensure a systematic arrangement of these components, a container was devised. This container is affixed to the athletes' wrists and ankles using an elastic band equipped with Velcro fasteners (Figures 4 and 5). The core of the SPERTA system, which is also the main contribution and innovation of this work--as it is what allows all components to contribute to the correct and efficient functioning of the system--is the software. This has been developed from scratch, enabling the integration of all system components in terms of communication, collection, storage, analysis, and the presentation of data to the user. It also provides an accessible and intuitive user interface for athletes and coaches to interact with the system, adding and/or receiving information, through an application for Windows operating systems. This interface provides the necessary operations and functionalities, thus allowing information to be presented and interpreted correctly. Figure 3: ESP8266-based mini Wi-Fi board (**a**), accelerometer and gyroscope module GY 521 MPU 6050 (**b**), power management module (**c**), and battery (**d**) connection diagram (red positive, black negative). Figure 2: System architecture framework. The SPERTA system was developed with the aim of creating a tool capable of evaluating the performance of Taekwondo athletes in real time. This system is made up of different elements, with different functionalities, which together allow the collection, storage, analysis, and availability of data from athletes' training sessions. These elements are a 3D camera, motion sensors, and a computer. The 3D camera used is the Orbbec Astra with RGB camera and depth sensor, to capture the athletes' movements during training. The motion sensors, developed for the system, consist of an ESP8266 board with Wi-Fi along with a GY 521 MPU 6050 sensor (accelerometer and gyroscope) and a 3.7 V 190 mAh Li-Po Battery. We have considered a total of four motion sensors, as they are placed on the extremities of the upper and lower limbs of the Taekwondo athletes. The software was developed from scratch in C# with Visual Studio 2017 IDE; this is a key component of the framework, as it allows the aggregation of all elements. Integrating the NuitrackTM SDK enables 3D human skeleton tracking; more specifically, it tracks the various joints and provides the coordinates of these joints in a three-dimensional environment. The software delivers and stores athletes' movement data, performing and presenting the calculation of speed, acceleration, and force values. To perform this task, the framework software receives  
Figure 4: Positioning of the developed motion sensor on an athlete’s wrist. Figure 5: Positioning of motion sensors on a Taekwondo athlete’s wrists and ankles. data from the 3D camera and movement sensors and analyzes the data received, which are saved and made available to athletes and coaches via the application interface, offering valuable feedback for evaluating athletes' performances. The SPERTA system's characteristics are carefully outlined to offer a technological solution aimed at assisting coaches in minimizing the duration required for evaluating an athlete's performance, thereby facilitating a swifter enhancement of the athlete's proficiency. By providing instantaneous feedback and precise data, this system empowers coaches to make well-informed choices and modify their training regimens to steer athletes towards more effective training methods, ultimately rapidly enhancing their performance. Consequently, it plays a pivotal role in advancing Taekwondo training and performance evaluation through the integration of technology, motion analysis, and real-time feedback.