DEVELOPMENT OF A MECHATRONIC SYSTEM FOR DETERMINING THE STRUCTURAL AND OPERATIONAL INTEGRITY OF MACHINE TOOLS

Abstract

Machine tools requires optimal performance to ensure accurate surface finish of manufactured machine parts. It is also necessary to continuously collect information about the machine tool integrity or health status, but while specifications related to performance of machine tools, machining processes, cutting tools, and materials may already exist (in form of standards), the means and methodology to combine the information in order to generate optimum machining conditions with expected outcomes still needs development. Hence, there is an urgent need to continuously monitor its integrity. The integrity factors, examined in this study, include the structural factors (the rigidity, motion analysis and the physical elements), the operational factors (alignment, straightness, parallelism, repeatability, precision and other operational factors), installation and foundation, the age and service history, the electrical components, the mechanical components (hydraulic, pneumatics, etc.) and also the work environment. This study employed the principles of mechatronics to determine both the structural and operational integrity of machine tools by developing a model to determine and categorize the structural and operational factors affecting machine tool integrity. The developed software connected seamlessly and automatically with Integrity Evaluator 1.0, and integrity data were obtained from the system for analysis in the form of aggregated attributes from the connected component sensors in real time. This provided a computer-based composite measure of the total integrity of machine tools and also a basis for the developed software’s recommended remedial actions. The developed model was further implemented by developing a mechatronic system, named Integrity Evaluator 1.0, using Arduino Mega 2560 micro-controller technology and connecting different component sensors for automatic data collection and processing procedure. The developed python programming software named, InteGmac was successfully tested using a Colchester Mastiff centre lathe and a Boxford 11-30 Industrial lathe as case studies and the entire mechatronic system monitored and improved the machine tool integrity. The InteGmac software enabled the improvement of machine tool elemental integrity values by recommending remedial actions carried out by the operator to improve the pressure readings from the initial hydraulic and pneumatic output pressures of 15 psi and 4.7 bar to manufacturer’s specification of 15.6psi and 6 bar respectively, the electric motor speed readings from the initial output of 1345 rev/min to manufacturer’s standard of 1400 rev/min and also by minimizing the offset and angular misalignment on the headstock, toolpost and tailstock to 0.0001mm on all specified 4-axis. This resulted to integrity improvement from 92.10% to 96.18% and 78.24% to 95.78% in the respective cases studied. Similar comparable results were obtained from follow up tests, which validated the performance of the developed mechatronic system.