International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

The rapid evolution of Industry 4.0 emphasizes not only automation and connectivity, but also the seamless integration of humancentric cyber-physical systems (CPS). This paper presents a secure, interoperable wireless communication framework based on the emerging Matter and Thread protocols, designed for real-time, local, and privacy-aware interactions between people and machines. While traditional wireless IoT protocols such as Zigbee and Bluetooth face challenges with fragmentation, lack of interoperability, and limited security models, Matter and Thread offer a unified, IP-based mesh network that is vendor-neutral, scalable, and designed with end-to-end encryption and device attestation by default. We apply this architecture to a practical use case in assistive IoT: enabling users with disabilities to interact with smart environments through secure, low-power wireless devices. This includes wearable panic buttons, smart locks, and environmental sensors that respond in real time, even in cloud-disconnected conditions, which is a critical requirement for safety in CPS. The system also supports multi-platform integration (Android, iOS, embedded Linux) without duplicating infrastructure. The paper presents a modular threat model, performance analysis of secure onboarding and encrypted control flows, and discusses deployment challenges in real-world industrial or healthcare automation contexts. This approach demonstrates how inclusive, secure-by-design wireless CPS can be realized with current technologies, contributing to more resilient and human-aware Industry 4.0 systems.

The authors propose the development of a framework using simulation modelling technology. The aim is to simulate the behavior and the interaction and interoperability of the components of the modern communication infrastructure of the national security systems in various crises. The focus is on cyber security and cyber defence, from the point of view of risks and threats to the security of communication infrastructure such as disasters and other crisis situations.

In this paper, the problems in redesigning a new track layout of an existing railway station according to the reqirements in the TSI “Infrastructure” and Ordinance No. 55 are examined and analyzed in the case of maintaining mainline operation during construction. The paper has been compiled on the basis of experience in designing the track layout of 3 existing railway stations from the Bulgarian network, as well as experience working with the current regulations and interoperability reqirements of the railway systems in the EU. The necessities for making changes in vertical and horizontal track alignment and switch layout are considered in opposition to the technolog ical, electrical and gauge limitations when carrying out construction works without the complete disruption of railway traffic. The conclusions of the report are formulated as guidelines for good practices when redesigning an existing layout – the practices that fully satisfy the imperative norms and balances between contradictory  equirements.

Interoperability for newly adopted countries in the EU is key to trains safety. Calculating the braking force used by the Leaflet 544-1 of the UIC Leaflet [1] brake elements is important for safety when running trains in the braking mode.
The researching of the facts shows that Regulation 58 [2] is harmonized with the contents of UIC Leaflet 544-1[1] and EU Regulation No 1302/2014 [3]. The test is to be used for the interoperability of the technical infrastructure in connection with Commission Regulation (EU) No 1299/2014 of 18 November 2014 [4] on technical specifications for interoperability with respect to the infrastructure subsystem of the railway system in the Union concerned.
When designing the rail lines used braking calculation, made by easy way remain based on the friction of the pads on the wheel surface, but it is not related to the examples in the UIC Leaflet 544-1 [1].

In view of the projects, which are being implemented in the second programming period 2014-2020 by the metropolitan municipality, a reconstruction of Graf Ignatiev Blvd was planned. An important part of it is the construction of the railway track. In fulfilment of the requirement for the elaboration of a diploma thesis on this topic, a number of options for implementation of the project, which apart from applied have a cognitive value. They meet the requirements for interoperability of technical infrastructure in relation to Commission Regulation (EU) No 1299/2014 of 18 November 2014 concerning the technical specifications for interoperability relating to the infrastructure subsystem of the rail system in the European Union [3].

This paper presents the developed domain ontology of the equipment in manufacturing systems in order to be used in the field of reconfigurable manufacturing systems (RMS). The ontology meets the requirements of the meta-class "Equipment", which is part of the developed meta ontology based on the standard for integrated systems for the production and management IEC / ISO 62264. The article explains various properties and class restrictions of the developed ontology. Web Ontology Language (OWL 2) and Protégé 4.3 as an editor and knowledge acquisition tool are used. Special attention is given to the use of ontology reasoning to infer additional information from the facts stated explicitly in ontology – an important feature, used to perform classification, sorting and assembly operations and consistency checking.

This paper presents an approach for software development that generates control programs in the field of reconfigurable manufacturing systems. The proposed approach proposes the use of developed domain ontologies merged in a meta ontology which is based on the standard for integrated production systems and management IEC / ISO 62264. The article addresses the main graphic elements of the software that are being developed as well the principle of generating control programs.