WIRELESS SENSOR SYNCHRONIZATION METHOD FOR MONITORING SHORT-TERM EVENTS

Abstract

Topicality. The key part of experimental research is obtaining the most accurate data about the studied object or event. Often, it is necessary to record parameters of processes that are c hallenging to precisely localize in space and time. The process or event under consideration can occur very rapidly, within fractions of a second, making it difficult for the researcher to deploy and configure recording equipment. This necessitates the creation of a network consisting of numerous recording devices to not miss critical events related to the studied process and obtain a sufficient volume of experimental data. Another issue is the synchronization of data obtained from different measurement devices. Spatially distributed recording devices must operate with a high degree of autonomy, leading to discrepancies in timekeeping and the need for synchronization. In processes with sub-millisecond durations, imperfections in timekeeping at each node have a significant impact: undetected and unaccounted discrepancies can lead to distortion or a misunderstanding of the overall picture of the studied process or event, even after acquiring all the necessary data. This is why the development and improvement of methods for synchronizing data recording nodes in distributed wireless sensor networks is important and urgent task. Task statement. One practical application of the proposed solution is the study of injuries caused by the penetration of foreign objects with high kinetic energy into the human body. These studies are conducted using artificial simulators of the human body made from composite materials and ballistic gelatin, with implanted electronic devices for recording changes in physical parameters. Results and conclusions. The article presents a hardware and software method, along with the technical implementation of the process for synchronizing the local clocks of wireless nodes, integrated into a unified information-measurement system located on the simulator. The proposed method allows achieving synchronization accuracy of no more than 12 μs/second using low-cost commercial off-the-shelf components. The practical part of the research discusses microprocessors from the ESP family, which, in general, provide sufficient time synchronization accuracy when using the proposed method, allowing for cost-effective node development within the system. The proposed method can also be applied in other fields, such as measuring vibrations in electrical machines and engines, as well as structural health monitoring.