Design and Development of a Distributed System for Monitoring of Machine Tool Behavior

The following thesis describes the development of a distributed system for the monitoring of numerical control machine tools. This work discusses all the design steps from the conceptualization of the hardware architecture to the development and implementation of monitoring algorithms. In the first chapter the state of art in machining automation will be presented, with a particular focus on monitoring and control system for machining operations. The second chapter describes the architecture of the proposed system both from the hardware and the software side. The third chapter goes into detail of the developed monitoring algorithms intended to the application on milling machines. The implementation and results of experimental tests will be discussed. Finally the fourth chapter proposes a new approach applied to the control of linear motion systems. The work presented in this thesis belongs to the applied research field that aims to enhance the automation level of machine tools by developing innovative techniques for the monitoring and control of machining process. The proposed monitoring system has been developed considering as key requirements the possibility to properly operate in several working conditions, the complete integration with the machine tool structure and the ease of use for unskilled personnel. The developed algorithms include the monitoring and mitigation of cutting vibrations, the detection and diagnosis of faults in spindle bearing and the emergency halt of the machine in case of collision. The resulting system provides a flexible and scalable framework easily adaptable to the specific machine tool and machining application. The monitoring tasks allow a fast setup and their execution is mostly automated, requiring a limited interaction with the machine tool end users. In conclusion the monitoring system improves the automation level of the machine tool providing a better control on the process execution. In addition it facilitates the assessment of the machine behavior allowing the objective evaluation of the operative conditions providing a useful support tool for the machine operator.