Advanced vibration processing techniques for condition monitoring and quality control in i.c. engines and harvesting machines

The topic of this thesis is the development and the implementation of advanced vibration processing techniques for machine condition monitoring and diagnostics with two fields of applications: the quality control of I.C. engines by means of cold tests, and the monitoring and control of harvesting processes. Thanks to this research study it is possible to understand which of the vibration signal processing techniques is effective for an easy quality control and for the diagnosis of different assembly faults. Moreover, the limits and drawbacks of both monitoring and diagnostic procedures are shown.The originality of the first part of the research mainly concerns the use of vibration measurements for the quality control of engines at the end of the assembly line while the greater part of methods used for cold test applications focuses on pressure and torque measurements. The second part of this thesis concerns the analysis of relationships between the harvesting process parameters relative to a non-conventional harvesting machine and its vibration response. The main original contribution of this second part concerns the use of the vibration signal as an effective way to monitor the harvesting process. It can also be considered as a proper quality control indicator for the user during field operations