This thesis is part of the SOCRADES project, a European research and advanced development project with the primary objective to develop a design, execution and management platform for next-generation industrial automation systems. In the specific case of work it concerns the networked control systems.
These are becoming more important in the industrial automation yield thanks to the many advantages introduced by the networks. In fact, the use of a network to connect the devices permits to eliminate unnecessary wirings, reducing the complexity and the overall cost in designing and implementing the control systems.
In the last years the fast spread of the wireless technologies has opened new scenarios for the communication in the automation field. The benefits introduced by the use of wireless communication in the networked control system are many. First of all the simplicity and the convenience of the sensors placement. The price to be paid is a lower reliability due to the interference that can easily affect the medium (radio frequencies) with the consequent possible loss of communication.
This work is focused on the study of the problem of losing packets (the information in a wireless network is formed by packets of bits) in a WirelessHART networked control system and on the possible solutions to avoid the problem. WirelessHART is a wireless protocol that provides a low cost, relatively low speed (e.g., compared to IEEE 802.11g) wireless connection. The aims of the thesis are multiple, first of all the implementation of a tool that permits to simulate a wirelessHART network.
In fact, since it is a quite new protocol, the most used network simulators do not give the possibility to simulate WirelessHART networks. This simulator has been implemented modifying the original version of the TrueTime network simulator, adding this new protocol and some other functions to make the simulator as close as possible to the reality. Another objective of the thesis is to study the effects, and the possible solutions, of the loss of communication in a wirelessHART network.
The last part of the thesis deals with a level control problem in a mineral flotation plant and with the possibility to use a wirelessHART network for that plant.
Author: De Biasi, Mauro