Application And Research On Power Line Communication Networks For Plant Factory

As a highly integrated intelligent ecosystem, the large plant factory has become a vital pattern to develop the agriculture in future. Therefore, it’s of great significance to carry out the research on the plant factory. The communication network, connecting to all the equipment in the plant factory, is the core of integrated system and traditionally adapt to the bus technology that usually used in industry. In fact, the bus technology is highly reliable and real-time under the circumstance that the communication nodes are few. While it might be confronted with complex problems which are hard to solve and high-cost when large number of communication nodes appear. This article mainly puts forward the establishment of core communication network by adopting the power line carrier technology. Through taking the existing distribute line as the medium of data transmissions, this technology can solve the problems of complex wiring and cost created when adopting the industrial bus technology.Therefore, this paper mainly focuses on the high-performance power line core control network. Large numbers of researches on the characteristics of power line and algorithm of power-line network reveal that, firstly, the electric power line channel, characterized with high complexity and strong disturbance, as well as the multipath effect strongly influence the power line communication; secondly, the algorithms applied in the power- line network produce large network overheads or not adapt to the changing channel of power line in most cases. Nowadays, many researchers have solved the unreliability of physical channel by adopting the spread-spectrum technique and the OFDM(orthogonal frequency division multiplexing). This paper puts forward the algorithms(PLC-TR) of power-line network that based on the multi-way sorting tree and the routing algorithms(PLC-OTR) of tree as the improved one, aimed at decreasing the data conflict by reducing the sending of redundant package, simplifying the routing rules and increasing the reliability of sing hop. Simulation results show that this algorithm has performed well in the aspects of package delivery, average end-to-end delay and network throughput.In order to verify the real performance of the algorithm, this paper also conducts the design of hardware system and communication protocol, including PLC communication nodes, main controller in the plant factory, the LCD control panel in the plant factory, network layer and communication protocol of application layer, etc. Experiments show that the core router control network, composed by PLC nodes, shows good performance in communication time delay and the delivery of package. The application test for the plant factory mainly contains the local control test and remote control test that goes through the PLC core control network, both the two achieving good results in the two-week test.