| Abstract [eng] |
The Internet of Things has found application in many fields. It provides additional services and opens new possibilities by connecting various devices, which are not smart in nature, to the internet. Precision agriculture is one of the fields, which are expected to benefit from the IoT. The main problems with IoT are the absence of internet connectivity in “things” and security concerns. The internet connectivity problem is usually solved by using a gateway device to connect a local network to the internet, while security is still an open issue. In the industrial automation sector security and device interoperability issues are addressed by a new OPC UA standard. In this thesis, an OPC UA based gateway device is developed and its suitability for IoT applications is studied. The main focus is on its applications in agriculture. During the course of this thesis, an OPC UA based data exchange solution for IoT was developed and was found suitable for agricultural applications. A literature review was done to identify the main data sources and applications of IoT and cloud services in agriculture. Then, the data transfer requirements for these applications were established. An overview of OPC UA standard was done. A flexible model for data aggregation into the OPC UA server from a wide diversity of field devices was proposed, detailed and implemented. The proposed concept was demonstrated to be feasible by aggregating data from various sources (wireless sensors, machinery, camera) into the OPC UA server and then accessing it remotely over the internet. The experiments were carried out to investigate the performance of data aggregation from field devices into the OPC UA server, as well as the performance of data acquisition from the OPC UA server via various connection options (Ethernet, Wi-Fi, VPN). The power consumption of the developed prototype was also tested. |
