System for monitoring and analysis of distributed parameters and fire safety of a Smart home
Authors: Земский Г.Т. , Амелин И.Э. , Кондратюк Н.В. 
Published: March 2023

В статье сообщается о принципе действия, составе и результатах испытания системы обеспечения безопасности «умного дома». Показано, что в отличие от пожарных извещателей (в том числе газовых), реагирующих на изменение химического состава атмосферы, вызванного воздействием пожара, автоматика «умного дома» извещает владельцев жилища об отклонениях в доме от заданных нормальных параметров до возникновения пожара. При этом возможно устранение причин изменений параметров атмосферы как по команде владельца жилища, так и по заранее введенной программе. Апробация системы мониторинга основных параметров безопасности жилища показала перспективность данной системы для раннего предупреждения о нештатных ситуациях в жилище.
The purpose of this article is to describe the purpose, composition, functionality and prospects for using the system for monitoring and analyzing distributed parameters (SMARP) for collecting, storing and analyzing data on the state of observed objects. The purpose of the article is to test the possibility of long-term monitoring of distributed parameters. Distributed parameters are any characteristics of observed objects that can be measured by technical means and located in arbitrary places. They include temperature, humidity, pressure, concentration of gases, aerosols, coordinates on the ground, speed, electrical voltage, current, etc. Since monitoring involves documentation (accumulation of observed parameters in a database (DB)), the statistics and dynamics of these parameters become available for analysis, which improves the characteristics of detecting an abnormal situation. The system can be represented as a tree structure. Sensors are combined into a device that contains a microcontroller that manages the polling of sensors and sending information either directly to a web server if the microcontroller is in the Wi-Fi network coverage area or via a radio channel to another microcontroller with Internet access if the first one is out of coverage area Wi-Fi networks. Devices, in turn, are combined into an object. Each object has its own credentials, which allows you to organize the separation of data access rights on the web server in the context of objects. The received data is stored in the web server database, processed by an algorithm that generates a decision (control vector), which is sent to microcontrollers as part of a response to their data. A “personal” response is sent to each microcontroller, to which it reacts according to the program available in it. The system is easily scalable by registering new objects and devices on the web server. In the system there were used microcontrollers ATmega328, ESP8266, ESP32. Widely used sensors based on tin dioxide MQ-5 are installed as gas concentration sensors. The data received by the web server are stored in the database. A registered and authorized user has access to the collected data and the results of software processing from any device with Internet access (PC, laptop, tablet, smartphone). The results of software processing include information about the excess of the values of the observed parameters over the established critical levels, information about negative and threatening trends or their absence, as well as the results of system self-diagnostics. Important information about the state of observed objects can be sent by the system to responsible persons by e-mail and in the form of a message to the Telegram messenger, and in some cases in the form of SMS and a telephone robotic call. When the observed parameters reach critical values, sound and light notification is possible by devices installed directly on the observed objects. The use of a radio channel for communication between microcontrollers and a central microcontroller makes it possible to place sensors at a considerable distance from the Internet access point – in a line-of-sight zone up to 1 km. Data are collected, documented and processed in real time. Data and processing results are available online from anywhere via the Internet. Access to data is carried out through the web browser of a personal computer, through a mobile application installed on the phone or through the chat bot of the Telegram messenger. The convenience of using the Telegram messenger is due to the fact that the notification will be received by all interested persons and responsible employees, regardless of their location in the coverage area of the mobile operator or available Wi-Fi networks. In addition, the system will generate a report on an emergency situation, which will be available to an authorized user on the site, and also sent to the responsible person by e-mail. For operational control of critical equipment at facilities, the system provides the connection of the information processing module with actuators, which, upon receipt of the appropriate command, are able to shut off the supply of gas, water, electricity, and also launch the fire extinguishing system. The algorithm for passing the command to start the actuators can be configured depending on the type of object (its purpose, fire hazard category, etc.). The algorithm can directly control the actuators or request confirmation from the system operator. Actuating devices are connected to a “smart relay”, which is a set of relays controlled by a microcontroller connected via the Internet to a web server, which gives the microcontroller a developed solution (control vector). The described configuration allows to control executive devices located in an arbitrary location with Internet access or within the coverage area of a cellular operator. The system for three users, consisting of 11 devices (3 sensors in each device), 2 “smart relays” was tested during the year. Remote monitoring of parameters was carried out. The system showed stability in operation. One abnormal situation was identified with the leakage of household gas through a micro-hole in a flexible hose. False alarms of the MQ-5 sensor were observed for the smell of orange (and tangerine) and shoe care spray, the sources of which were in close proximity to the sensor. The probability of a false alarm is reduced by optimizing the sensor threshold.